Fruit Trees for Storm Lake, Carroll and Sac City, Iowa

On January 16, 2009, NOAA's Sac City station, down in the North Raccoon valley at 1,210 ft, read −31°F, the coldest reading in its 104 years on file. In the same cold snap Storm Lake, 19 miles northwest and about 230 ft higher, bottomed at −22°F, and Denison at −20°F. That 9°F to 11°F spread is the first thing to understand when you're picking fruit trees for Storm Lake, Carroll and Sac City.

The map covers this corner of Northwest and west-central Iowa from Truesdale south to Willey: Storm Lake, Alta and Newell; Sac City, Lake View, Wall Lake and Odebolt; Carroll, Glidden, Breda and Arcadia; Denison and Vail in Crawford County; and Lake City on the east side. Type your address in the box on the map to get the number for your own place, and the list of what we sell that has come through it.

How to read this map

The big number is the 30-year planning low, the same number our cold hardiness calculator uses (NOAA station records since the 1995-96 winter), plus a small nudge for the ground right around you. It's a safe number to plan around, not the record. The MFTC zone is that number in half zones; the typical winter is an average year's coldest night, the kind USDA's map uses. The spring layer shows how much warmer or colder a spot runs than Storm Lake on a still, clear night at bloom.

Storm Lake, the reference, plans for −27°F (MFTC zone 4a), typical winter −16°F. The middle of the growing ground plans for −28°F, and half of it falls between −30°F and −27°F. The cold end, −31°F to −32°F, is Hanover southwest of Alta, the Casino Beach shore of Storm Lake, the flat country around Varina, Rusk and Lavinia, and Vail on the valley floor. The warm end, −24°F to −25°F (zone 4b), is the southeast: Carroll and its Rolling Hills and Collison Addition neighborhoods, Glidden, Lidderdale and the Willey bench.

Why the map looks the way it does

Two lines run through this map. One is the Missouri-Mississippi divide. Alta sits on it at about 1,516 ft, the highest town here, and it runs south past Schaller to Arcadia, first named Tip Top for its spot on the divide. East of it the North Raccoon (past Sac City) and the Middle Raccoon (the old "Middle Coon," through Carroll) drain to the Mississippi; west of it the Boyer runs southwest through Denison toward the Missouri. The other line is the west edge of the Des Moines Lobe, the last glacier into Iowa, gone by about 12,000 years ago, which runs by Storm Lake and through Carroll County. Inside it the till is young and hummocky, with closed hollows holding 8 to 20 ft of peat and muck, ground that had to be tiled. West of it, around Denison, is the Southern Iowa Drift Plain: loess over old till, long crests and broad troughs, and a branching creek network.

The divide towns sit roughly 150 to 265 ft above the Raccoon and Boyer bottoms, and the lowest named places, Grant City southeast of Sac City and Kimze southwest of Denison, are at 1,164 ft. On a clear, calm night the uplands lose their heat to the sky, and the chilled air slides into the valleys and pools under warmer air. That fits the Sac City reading in 2009, and it's why Denison's town center, 120 ft above its floor, plans for −29°F while the floor within 3 miles runs −32°F. Denison and Lake City have the coldest floors of any town on the map, −32°F.

On the Lobe the cold has fewer ways out. Newell and Fonda sit on slopes under 1 percent, and Newell's ground was once swampy. A closed hollow fills with cold up to its lowest notch before it spills, and wet hay ground and peat run cold because they're low, grassy and often organic. So the flat northeast, from Newell and Fonda to Varina and Rusk, plans for −30°F to −31°F. Off the east edge, Rockwell City matched its 1912 record of −35°F on January 30 and 31, 2019, in a cold snap when Carroll bottomed at −20°F.

The warm end is the southeast. The long-record Carroll station has the mildest 30-year number of any station still reporting here, −25°F (the airport's is −26°F), and in the 2009, 2019 and 2021 outbreaks Carroll read −23°F, −20°F and −22°F while Sac City, Denison or Rockwell City went to −31°F to −35°F. Some of that may be town heat (the map gives built-up ground up to 2.5°F). Take it with some salt, though: over 122 years on file Carroll's average coldest night, −19°F, matches Storm Lake's and Sac City's, and it was the coldest station here in February 1958 (−31°F).

The lakes are shallow. Storm Lake runs about 3,100 acres and 20.3 ft at its deepest, Black Hawk Lake 957 acres and 20 ft, and shallow lakes freeze. Snow-covered ice is just a flat floor radiating to the sky; as Wisconsin's state climatology office puts it, lakes shelter their shores only when they're relatively free of ice. So the lake doesn't help the winter low: the town on the north shore plans for −27°F, Lakeside on the east shore −30°F, Casino Beach −31°F. It may help in fall while it's open (the Storm Lake station has the latest median first 28°F here, October 24), though we haven't found a study of it. Its early last spring frost, April 22, nearly matches that of the Denison station (April 24), also high at 1,401 ft, which points to height more than water.

Then there's wind. On open farm country an inversion usually holds only while the wind stays under about 3 to 5 mph (Washington State's orchard numbers), and some outbreaks fill everything evenly: in February 1996 every station landed between −26°F and −28°F. Wind moves snow too: in the March 1870 blizzard, near −35°F for about 36 hours, the hollows drifted up to 20 ft deep while exposed knobs were swept bare. Snow keeps roots alive, so a windswept rise that runs warm on still nights can be the worst place for roots in a snowless cold snap.

Storm Lake, Lakeside and the lake shore

Storm Lake grew up on the north shore after the railroad came in 1870, while the first settlement, "old town," stayed on the southwest shore. The town plans for −27°F (zone 4a), typical winter −16°F, and sits in the warmest tenth of the ground around it; within 3 miles the floor runs −30°F and there's no bench ground. Height (40 ft above the floor) helps, and likely so do streets and buildings on a still night. The long-record station (107 years on file) has a 30-year number of −26°F; the automated airport station, at 1,476 ft, −29°F.

Lakeside, the old cottage and resort shore on the east side, plans for −30°F (zone 3b), typical winter −19°F, and runs 3°F colder than Storm Lake at bloom. Casino Beach, southwest of town, plans for −31°F. Truesdale, Sulphur Springs and Juniata, out on the farm ground, plan for −29°F. On a town lot, Liberty (−30°F) and Freedom (−35°F) apples, both on Iowa State's disease-resistant list, Bartlett pear (−35°F), Superior plum (−35°F) with Toka (−45°F) to pollenize it, and Lapins sweet cherry (−35°F) all fit. On the shore, stay with fruit that has come through −35°F or colder. North of Truesdale toward Spencer, the Spencer, Spirit Lake and the Iowa Great Lakes map covers you.

Alta, Schaller, Odebolt and the divide

Alta, on the divide 6 miles from Storm Lake, is a bench 100 ft above its floor: −27°F (zone 4a), typical winter −16°F, and 4°F warmer than Storm Lake at bloom, with the floor around it at −31°F. NOAA's old Alta station (1894 to 1958) read −36°F in the January 12, 1912 cold that set the map's records, but only −17°F in February 1958, 14°F warmer than Carroll in the same cold snap. Hanover, 6 miles southwest on a toe slope only 30 ft above its floor, has the coldest planning low of any named place on the map, −32°F (zone 3b). Plant it like a bottom.

Schaller plans for −29°F, with benches around it at −27°F. Odebolt, near the head of Odebolt Creek, plans for −26°F, typical winter −14°F, with benches at −24°F; in the years its two old stations overlapped with Denison's (around 1898 to 1913), Denison's coldest night of the year ran a median 3°F to 4°F colder. West of Odebolt, Arthur sits right on its floor at −27°F but runs 3°F colder than Storm Lake at bloom, fine for winter and frosty at bloom. Alta's bench is apricot ground: Westcot (−45°F) and Sungold (−40°F), with Siberian C peach (−35°F) and Black Gold sweet cherry (−35°F).

Newell, Fonda and the flat northeast

Newell sits on once-swampy ground near the upper North Raccoon, with the Raccoon River Heritage Wildlife Corridor 2 miles west. It plans for −30°F (zone 3b), typical winter −18°F, 1°F colder than Storm Lake at bloom; within 3 miles the floor runs −30°F and the warmest tenth only −28°F. Fonda, 8 miles east, plans for −30°F (zone 3b) over a coldest tenth of −32°F, and Varina and Rusk, to the north, −31°F. Hillside Orchard at Newell grows 16 apple varieties here, including Cortland, Sweet Sixteen and Haralson, all of which clear −30°F: Haralson (−45°F), Sweet Sixteen and Cortland (−40°F), though Iowa State flags Cortland as disease-prone. Add Wealthy (−50°F), Ure pear (−40°F) on the rises and Evan's Bali tart cherry (−45°F).

Sac City, Lake View and Lake City

Sac City sits in the rolling hills along the North Raccoon at about 1,260 ft, some of the lowest town ground on the map. It plans for −29°F (zone 4a), typical winter −17°F, and runs 1°F warmer than Storm Lake at bloom. Within 3 miles the floor runs −29°F and the coldest tenth −30°F, and the map finds no ground 100 ft above the floor. The station's 30-year number is −29°F, and its median last spring frost, April 29, is the latest of the six stations with frost data. Lake City, named for Lake Creek, a North Raccoon tributary, plans for −30°F, and its ground is the coldest of any town here: floor −32°F, coldest tenth −33°F, warmest tenth −30°F. Lavinia, to the north, plans for −31°F (zone 3b). East toward Fort Dodge, the Fort Dodge and Webster City map takes over.

Black Hawk Lake, at Lake View's east edge, is by the DNR's account Iowa's southernmost natural glacial lake, and in DNR ice reports it has frozen over earlier than Storm Lake. Lake View plans for −28°F (zone 4a), typical winter −15°F, 1°F colder than Storm Lake at bloom, with benches around it at −26°F. Wall Lake, 3 miles southwest, is the same: −28°F with −26°F benches. In this valley plant the low ground for −30°F to −32°F with Honeycrisp (−45°F), Zestar!® (−40°F), Meteor tart cherry (−40°F) and the applecrabs Kerr and Trailman (if you only plant one tree, make it one of those two), and save pears, plums and sweet cherries for the benches.

Carroll, Rolling Hills and Collison Addition

Carroll lies along the Middle Raccoon at about 1,276 ft, and the river is a soil line: the 1912 county history found gravelly "Carroll drift" east of it and loess on the bluff-capped western uplands. Carroll plans for −25°F (zone 4b), typical winter −14°F, and runs 3°F warmer than Storm Lake at bloom. The ground around town is tight: floor −26°F, benches −24°F. Rolling Hills, under a mile south-southwest of downtown on a toe slope, and Collison Addition, about a mile and a half north, both plan for −24°F (zone 4b), but both run about 1°F colder than Storm Lake at bloom, 4°F behind downtown. NC State's fruit people say 3°F to 4°F can separate no crop from a full one.

Carroll's long-record station shares the map's coldest record, −40°F on January 12, 1912, with Denison. Mount Carmel, 6 miles north-northwest on a bench 100 ft up, plans for −26°F and runs 4°F warmer than Storm Lake at bloom. Storm Creek rises north of it and meanders through a wide, level bottom; a 1912 drainage project there took in about 8,000 acres of wet land and Goose Lake, cold ground. Glidden, 7 miles east, plans for −24°F (zone 4b) with the mildest typical winter of any named place on the map, −12°F.

Carroll's town lots have the most room here: Contender peach (−30°F), with Blushingstar (−25°F) worth a try against a south wall (it came through −25°F at our place on January 13, 2024 without damage), Rainier sweet cherry (−30°F), Harlayne apricot (−30°F) and D'Anjou pear (−30°F). In Rolling Hills and Collison Addition, give apricots and cherries the highest corner of the lot.

Breda, Arcadia, Halbur and the Willey bench

Arcadia, the old Tip Top, plans for −26°F (zone 4a) on a 4 percent toe slope 70 ft above its floor and runs 4°F warmer than Storm Lake at bloom. Breda also plans for −26°F but runs 1°F colder at bloom. Halbur, on a 10 percent slope, plans for −27°F with benches around it at −24°F, and Roselle, 70 ft up southwest of Carroll, −25°F and 3°F warmer than Storm Lake at bloom. Westside, west of Arcadia only 10 ft above its floor, drops to −29°F.

Willey is the standout: a bench 140 ft above its floor, the most of any named place on the map, at −24°F (zone 4b), typical winter −13°F, and 6°F warmer than Storm Lake at bloom. Santa Maria Vineyard and Winery in Carroll grows part of its grapes at Willey, and grapes forgive spring frost less than most tree fruit. Ground like this suits Marquette and Frontenac (−35°F) or La Crescent (−40°F) grapes, and the early bloomers: Sungold and Westcot apricots, Lapins cherry, Contender and Siberian C peaches.

Denison, Vail and the Boyer valley

Denison, the Crawford County seat, is loess-covered drift plain with the Boyer cutting southwest through town. The town center sits 120 ft above its floor and plans for −29°F (zone 4a), typical winter −15°F, and its spring reading is the best of any named place on the map, 7°F warmer than Storm Lake. The floor within 3 miles runs −32°F, and Kimze, on the river bottom 2.4 miles southwest, plans for −29°F and runs 4°F colder than Storm Lake at bloom, 11°F behind the town. Sunset Village, on an 8 percent slope a mile and a half southwest, also plans for −29°F but reads even with Storm Lake at bloom, because the cold drains past it.

North of town, Deloit, on a toe slope 70 ft up, plans for −30°F but runs 6°F warmer than Storm Lake at bloom; Vail, flat on the valley floor to the east, plans for −31°F (zone 3b) and runs 3°F colder. The sharpest pair of named places on the map is northeast of town: the hamlet of Boyer, on a 12 percent slope, plans for −29°F and runs 3°F warmer than Storm Lake at bloom, while Boyer River, 1.6 miles away on the valley floor, plans for −29°F and runs 8°F colder. The same winter, 11°F apart on a spring night. Put early bloomers on the Denison bench and the Deloit slopes: Westcot and Debbie's Gold (−50°F) apricots, White Gold sweet cherry (−35°F) and Bartlett pear. The bottoms are for apples like Haralson and Wealthy, Honeyberry and currants.

Spring frost and bloom, from Storm Lake to the Boyer

NOAA station records for 1991 to 2020 put the median last 32°F frost at April 22 at Storm Lake, April 24 at Denison, April 28 at Carroll, Pocahontas and Rockwell City, and April 29 at Sac City; in a late year (1 in 10), as late as May 4 at Storm Lake, May 7 at Pocahontas and May 12 to 13 at the rest. Frost-free seasons run 158 days at Carroll, 159 at Sac City, 169 at Denison and 172 at Storm Lake (from 19 years of data). The two high stations, at 1,439 ft and 1,401 ft, have the earliest springs; the four at 1,210 to 1,240 ft run 4 to 7 days later. That fits cold drainage showing up in the light frosts, while the median last 28°F falls April 13 to 15 at all six. And the Carroll station, with the mildest winter number, has the shortest season: winter low and bloom frost are two different maps.

The spring layer is that still-night pattern drawn at full strength, and it swings hardest on the steeper ground west of the divide (the old Carroll County history notes the Missouri side is steeper). Open blossoms of nearly every tree fruit start dying at about 28°F (Michigan State's critical-temperature tables), so the spots reading 3°F to 8°F colder than Storm Lake (Boyer River, Kimze, Vail, Lakeside, Arthur) are the ones that can lose a crop the town keeps. Most fruit can lose half its blossoms and still crop. Michigan's old orchard surveys found ridges only 25 to 30 feet above the plain nearly as frost-free as high hills, and that's the scale here: the Denison and Willey benches, the Deloit and Boyer slopes, Alta, Arcadia and Mount Carmel all read 3°F to 7°F warmer than Storm Lake.

In 2012 a bloom frost cost Iowa growers about 90 percent of their fruit (the orchards named were in central Iowa). What to do: apricots, peaches, sweet cherries and pears go on the highest, best-drained ground you have, apples, haskap (open flowers take 19°F) and currants lower. A hedge, fence, road fill or tree line across a slope backs cold air up into the trees above it, so gap it at the low end. Through bloom, mow short and don't till; frost cloth at 0.9 oz per square yard gains about 6°F (Alabama Extension).

What the weather records say

The coldest readings in NOAA station records here came on January 12, 1912: Carroll and Denison −40°F, Alta and Pocahontas −36°F, Rockwell City −35°F. Storm Lake's coldest on record is −34°F (February 3, 1905) and Sac City's −31°F (January 16, 2009). Other big outbreaks, with each station's low in the same cold snap:

• January 22, 1936: Storm Lake −30°F, Carroll −22°F, Denison −21°F.
• February 3, 1996: −26°F to −28°F at every station.
• February 16, 2021: Rockwell City −33°F, Denison −32°F, Storm Lake −21°F.

PlantMaps lists Carroll, Denison, Lake City, Lakeside, Alta and Newell in USDA zone 5a (apparently the 2012 map), and a guide to the 2023 map puts most of northern Iowa in 5a: an average coldest night of −20°F to −15°F, about what the long-record stations here average. Ours run 3b to 4b because they're built on the bad night you plan for; NOAA station records show the worst night in about 30 winters runs a median 13°F below a station's average winter low.

What you can grow here

Carroll, Glidden, Willey and the warm southeast, −24°F to −26°F

Contender (−30°F) and Siberian C peaches, with Blushingstar (−25°F) worth a try on the warmest lots; Rainier and Lapins sweet cherries; Harlayne and Sungold apricots; D'Anjou and Bartlett pears; Stanley (−30°F) and Italian (−35°F) plums; Liberty and Freedom apples; Marquette and Frontenac grapes.

Most of the map, −27°F to −30°F

Haralson, Honeycrisp, Freedom and Wealthy apples; Bartlett and Cold Snap® (−40°F) pears; Superior plum with Toka to pollenize it; Lapins and Evan's Bali cherries; Westcot apricot; Siberian C peach on slopes with a warm spring reading; La Crescent grapes.

The cold bottoms and the flat northeast, −30°F to −32°F

Plant what has come through −35°F or colder: Haralson, Wealthy and Zestar!® apples; Kerr, Trailman and Centennial applecrabs (Ed Schultz saw zero winter injury on Centennial after a winter that hit −47°F); Ure pear on the rises; Evan's Bali and Meteor tart cherries; Pipestone and Toka plums; Westcot apricot only on your highest ground.

Bush fruit fits anywhere: Honeyberry and Montana Black Currant (−50°F), Red Lake currant and Nova raspberry (−40°F), and Aronia (−50°F). Plant at least two apple varieties that bloom together (most flowering crabapples will pollenize nearby apples, says Iowa State); hybrid plums need a pollenizer too. The pollination maps show the pairings.

Iowa State suggests EMLA 7 for a semi-dwarf apple and B9 or G41 for a dwarf, and warns that M26 is highly prone to fire blight. Roots are the weak link and snow protects them (at Ed Schultz's farm in Gallatin Gateway, Montana, Bud 118 apple rootstock has seen near −50°F under snow with no damage), so on a windswept rise use the hardiest stock you can get. Montana State recommends a 4 to 8 percent grade where cold won't settle. On the Lobe's tiled ground, test drainage first (dig 2 ft, fill it, let it drain, fill it again; under 10 hours is well drained); Iowa State says fruit trees in poorly drained soil often die within a few years. Don't replant where apples or pears recently died, and taper any watering from mid-August so trees harden off.

Fruit history here

Iowa was one of the top apple states in the early 1900s, until the Armistice Day freeze of November 11, 1940 caught trees unready after three days of warm rain. The 1941 crop came in at about 15 percent of its pre-storm level, and the industry never recovered. The 1912 Carroll County history called the county's soils suited to fruits and noted farm groves planted countywide, but named no orchards. Today there's Hillside Orchard at Newell, Williams Orchard at Denison and Santa Maria's vineyards at Willey.

Questions people ask

What growing zone are Storm Lake and Carroll, Iowa?

Our map has Storm Lake planning for −27°F, MFTC zone 4a (typical winter −16°F), and Carroll −25°F, MFTC zone 4b (typical winter −14°F). PlantMaps lists Carroll and Lakeside in USDA zone 5a, apparently from the 2012 map. USDA's zone is based on an average winter, ours on the bad night we plan for; Carroll's record is −40°F, from January 12, 1912.

When is the last frost in Storm Lake and Carroll?

NOAA station records for 1991 to 2020 give a median last 32°F frost of April 22 at Storm Lake and April 28 at Carroll, with a late year (1 in 10) running to May 4 and May 13. The last hard frost, 28°F, comes around April 15 at Storm Lake and April 14 at Carroll.

Can you grow peaches in northwest Iowa?

Iowa State says peaches and sweet cherries aren't reliably hardy in northern and central Iowa. Siberian C has come through −35°F, which clears every town on this map, and Contender (−30°F) clears most of it. Put them on a bench with a good spring reading, like Denison or Willey, not a river bottom.

Where are the frost pockets around Carroll and Denison?

Around Denison it's the Boyer bottom: the floor within 3 miles plans for −32°F, and the Boyer River hamlet reads 8°F colder than Storm Lake at bloom while the town reads 7°F warmer. Around Carroll, Rolling Hills and Collison Addition run about 4°F behind downtown on a bloom night, and Storm Creek's wide, wet bottom north of town collects cold.

Does Storm Lake keep the shore warmer in winter?

No. It's shallow, 20.3 ft at its deepest, and it freezes; by early March 2022 it had 12 to 15 inches of ice. Lakeside plans for −30°F and Casino Beach −31°F, colder than the town at −27°F. The open lake may help in fall, though; the Storm Lake station has the latest median first 28°F frost of the six stations, October 24.

Warmer spots, colder spots

Here's the number to plan for at named places on the map, warmest first. Each one is the 1-in-30-year low for that spot: the cold hardiness calculator's number from the same weather stations, sharpened by our microclimate model for the ground right there. Zone is our MFTC zone, set by that one bad night, not by an average.

The weather stations behind it

These are the long-record stations in and around this map, with each one's own numbers since the winter of 1995-96. The last column is this map's 30-year number right at the station, which won't match the station exactly: it's a blend of the stations around it, the way the calculator works everywhere.

Source: NOAA records through ACIS, winters 1995-96 through 2025-26. What the "carried forward," "gaps filled" and AWOS rows mean is explained in how our microclimate maps work.