Fort Madison, Iowa climate: Normal weather by month, frost dates and records
Fort Madison's normal year runs from 17°F January nights to 85°F July afternoons, with 39.4 inches of precipitation and 18 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.2°C, January lows of −8°C, July highs of 30°C, 1,000 mm of precipitation a year.
- NOAA stationFort Madison
- Station IDUSC00133007
- Location40.62°N 91.33°W
- Elevation530 ft (162 m)
- Population9,983
On October 23, the normal high in Fort Madison is 61°F and the normal low 42°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Madison.
- Jan 33° 17°
- Feb 38° 21°
- Mar 50° 32°
- Apr 62° 43°
- May 72° 54°
- Jun 82° 63°
- Jul 85° 68°
- Aug 84° 66°
- Sep 77° 57°
- Oct 64° 45°
- Nov 50° 33°
- Dec 38° 23°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Fort Madison each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 17°F. The most precipitation falls in June (5.16 in), the least in January (1.69 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 17°F | 24.8°F | 1.69 | 6.1 | 8 | <1 | 28 | 9 h 30 min |
| February | 38°F | 21°F | 29.2°F | 1.93 | 4.6 | 8 | <1 | 23 | 10 h 40 min |
| March | 50°F | 32°F | 40.8°F | 2.72 | 1.7 | 10 | <1 | 16 | 11 h 50 min |
| April | 62°F | 43°F | 52.4°F | 3.97 | 0.5 | 12 | <1 | 3 | 13 h 10 min |
| May | 72°F | 54°F | 63.1°F | 5.11 | 0.0 | 13 | <1 | <1 | 14 h 20 min |
| June | 82°F | 63°F | 72.5°F | 5.16 | 0.0 | 10 | 3 | <1 | 15 h |
| July | 85°F | 68°F | 76.3°F | 4.06 | 0.0 | 9 | 8 | <1 | 14 h 50 min |
| August | 84°F | 66°F | 74.7°F | 3.80 | 0.0 | 9 | 6 | <1 | 13 h 50 min |
| September | 77°F | 57°F | 67.1°F | 3.51 | 0.0 | 7 | 2 | <1 | 12 h 30 min |
| October | 64°F | 45°F | 54.7°F | 3.06 | 0.1 | 9 | <1 | 2 | 11 h 10 min |
| November | 50°F | 33°F | 41.3°F | 2.43 | 0.8 | 8 | <1 | 13 | 10 h |
| December | 38°F | 23°F | 30.2°F | 1.92 | 4.3 | 8 | <1 | 25 | 9 h 20 min |
| Year (annual) | 61°F | 43°F | 52.2°F | 39.36 | 18.1 | 111 | 19 | 110 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −8°C | −4.0°C | 43 mm | 15 cm |
| February | 3°C | −6°C | −1.6°C | 49 mm | 12 cm |
| March | 10°C | 0°C | 4.9°C | 69 mm | 4 cm |
| April | 17°C | 6°C | 11.3°C | 101 mm | 1 cm |
| May | 22°C | 12°C | 17.3°C | 130 mm | 0 cm |
| June | 28°C | 17°C | 22.5°C | 131 mm | 0 cm |
| July | 30°C | 20°C | 24.6°C | 103 mm | 0 cm |
| August | 29°C | 19°C | 23.7°C | 97 mm | 0 cm |
| September | 25°C | 14°C | 19.5°C | 89 mm | 0 cm |
| October | 18°C | 7°C | 12.6°C | 78 mm | 0 cm |
| November | 10°C | 0°C | 5.2°C | 62 mm | 2 cm |
| December | 3°C | −5°C | −1.0°C | 49 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00133007; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Fort Madison?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00133007.
When is the last frost in Fort Madison?
In Fort Madison, the last spring frost (32°F) comes after April 12 in half of years and after April 26 in one year in ten; the first autumn frost comes before October 25 in half of years and before October 11 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 121 year in 10 after April 26; 9 in 10 after April 1
- First autumn frost, half of years before
- October 251 year in 10 before October 11; 9 in 10 before November 6
NOAA puts the median frost-free season at 194 days, and the season without a hard freeze (28°F) at 215 days.
A hard freeze (28°F) comes after April 3 in half of springs and before November 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Madison in zone 6a in ZIP code 52627. By the map's own method, the average of each year's coldest night over 1991-2020, Fort Madison's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°F (30 complete years).
Frost dates for every NOAA station in Iowa · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00133007; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Fort Madison?
In a normal year in Fort Madison, 19 days a year reach 90°F (1 of them 100°F or more), 110 nights fall to 32°F or colder and 111 days bring measurable precipitation.
- Days at 90°F or more
- 19a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 110a normal year
- Days that stay below freezing
- 35high of 32°F or less
- Days with 0.01 inch of precipitation
- 111a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1893) is 107°F, on July 26, 1916; the lowest is −22°F, on January 12, 1974.
The wettest calendar year on that record is 1998, with 56.35 in; the snowiest season is 1961–62, with 42.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00133007; records: ACIS (NOAA Regional Climate Centers), station USC00133007. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Madison?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Madison, 4.1 kWh per square metre a day. September is the sunniest month (82%) and January the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.9 |
| February | 68% | 2.8 |
| March | 67% | 3.7 |
| April | 70% | 4.9 |
| May | 72% | 5.6 |
| June | 78% | 6.3 |
| July | 82% | 6.4 |
| August | 81% | 5.6 |
| September | 82% | 4.7 |
| October | 73% | 3.2 |
| November | 71% | 2.2 |
| December | 64% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Fort Madison need?
A normal year in Fort Madison brings 5,731 heating degree days, 7% more than the median U.S. place (5,373), and 1,119 cooling degree days, 23% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,602 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,244 | 0 |
| February | 1,002 | 0 |
| March | 753 | 1 |
| April | 387 | 7 |
| May | 134 | 73 |
| June | 12 | 235 |
| July | 1 | 352 |
| August | 2 | 303 |
| September | 67 | 131 |
| October | 336 | 17 |
| November | 713 | 0 |
| December | 1,080 | 0 |
| Year (annual) | 5,731 | 1,119 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00133007. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Fort Madison been warmer than normal lately?
2022 averaged 52.3°F, 0.1°F above the 1991-2020 normal of 52.2°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.7°F | +1.5°F | 45.52 | 19.0 |
| 2022 | 52.3°F | +0.1°F | 28.67 | 21.5 |
Over 57 complete years from 1955 to 2022, the station's annual mean temperature rose at a fitted 2.3°F per century (+0.13°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00133007; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Fort Madison's climate compare?
Fort Madison is warmer than 131 of the other 131 places with their own NOAA record in Iowa, and wetter than 120. Across the 7,247 U.S. stations with normals, its annual mean of 52.2°F is warmer than 50%.
In the Köppen classification computed from these normals, Fort Madison is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Fort Madison share this climate record?
6 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Nauvoo, IL910 people · 6 mi SW
- Dallas City, IL778 people · 9 mi E
- Denmark, IA738 people · 8 mi N
- Montrose, IA734 people · 8 mi SW
- Pontoosuc, IL98 people · 6 mi E
- Niota, IL4 people · 2 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Fort Madison's climate
What is the coldest month in Fort Madison?
January, with a normal high of 33°F and a normal low of 17°F. The warmest is July (85°F by day, 68°F at night).
Does it snow in Fort Madison?
Yes: 18 inches in a normal year, falling on 12 days with 0.1 inch or more, the most in January (6.1 inches).
What is the rainiest month in Fort Madison?
June, with 5.16 in of precipitation in a normal year; the driest is January with 1.69 in.
What plant hardiness zone is Fort Madison in?
The USDA's 2023 map puts Fort Madison in zone 6a in ZIP code 52627. By the same method at Fort Madison's NOAA station, the coldest night of a typical year reaches −8°F (30 years, 1991-2020): zone 6a.
How late can frost come in Fort Madison?
In half of years the last 32°F night comes after April 12; in one year in ten it comes after April 26. Waiting until April 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Iowa climateThe statewide normals and every place in the state
- Donnellson, IA12 miles from this station, 51.7°F a year
- Burlington, IA16 miles from this station, 51.9°F a year
- Keokuk, IA16 miles from this station, 52.1°F a year
- La Harpe, IL19 miles from this station, 50.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made