Sigourney, IA Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Sigourney's primary NOAA station, SIGOURNEY.
The climate verdict for Sigourney
Sigourney, Iowa has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 49°F. Its climate comfort score of 64/100 (good) lands mid-pack nationally, exceeding 49% of station-mapped location scores.
- 49°F
- yearly average temperature, NOAA normal
- 64/100
- comfort score, above 49% of station-mapped location scores
- 37.4"
- yearly precipitation total
- 174 days
- frost-free growing season
Sigourney: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00137678 · Sigourney, IA 49°F mean · 37.4" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 49°F
- RANK-COOL #2,401
- PHOTO-FINISH ≈ Iowa City
- PRCP-MID 37.4"
- SWING-WIDE 53°F
- COMF-MID 64/100
- LOAD-HEAT 6,641 HDD
- STN-1 USC00137678
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Iowa City, IA (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every IA station list.
- Sigourney (this station) 49°F
- Cold Arthur, NE 49°F
- Hot Ord Evelyn Shar…, NE 49°F
- Near Iowa City, IA 49°F
- Near Oglala, SD 49°F
Climate Living Index · Sigourney
Sigourney: 52/100 · grade D
Sigourney publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Sigourney, not an official NOAA rating. Rankings still use Comfort Score 64/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 37.4 in · 2.4 from 35 in | 91/100 · A |
| Normal heat + freeze calendar | 149 calendar days | 47/100 · D |
| Frost-free season | 174 days/year | 45/100 · D |
| Annual temperature balance | 48.9°F · 18.6° from 67.5°F | 36/100 · F |
Sigourney · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Sigourney is a continental Köppen climate: Dfa
Coldest-month mean 20.7°F and warmest-month mean 73.6°F place this station in continental, no dry season, hot summer climates (Dfa). Class Dfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, hot summer.
- Köppen code
- Dfa
- Group
- Continental
- Warmest month
- 73.6°F
- Coldest month
- 20.7°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Sigourney sits across the climate record
Three NOAA fields for Sigourney's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 35th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 52nd percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Wider than 88%
- Warmest-to-coldest month gap for Sigourney is large versus 6,861 complete station-years.
How Sigourney compares across U.S. station-mapped locations
Sigourney's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
64 49th percentile score exceeds 49% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). This entry sits in this band.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Sigourney's measured station temperature trend
MethodologyAcross 92 complete annual observations from 1897 to 2025, SIGOURNEY warmed at a fitted rate of 0.07°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Sigourney primary station fitted change +0.07 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 30°F (-1°C) | 12°F (-11°C) | 21°F (-6°C) | 1.2" | 30.1 | 0.0 |
| February | 35°F (1°C) | 15°F (-9°C) | 25°F (-4°C) | 1.5" | 25.8 | 0.0 |
| March | 48°F (9°C) | 26°F (-3°C) | 37°F (3°C) | 2.3" | 22.8 | 0.0 |
| April | 61°F (16°C) | 37°F (3°C) | 49°F (9°C) | 3.7" | 8.1 | 0.0 |
| May | 71°F (22°C) | 49°F (10°C) | 60°F (16°C) | 5.0" | 0.4 | 0.2 |
| June | 81°F (27°C) | 59°F (15°C) | 70°F (21°C) | 5.1" | 0.0 | 2.3 |
| July | 85°F (29°C) | 63°F (17°C) | 74°F (23°C) | 3.9" | 0.0 | 7.1 |
| August | 83°F (28°C) | 60°F (16°C) | 72°F (22°C) | 4.8" | 0.0 | 4.4 |
| September | 76°F (25°C) | 52°F (11°C) | 64°F (18°C) | 3.5" | 0.1 | 1.7 |
| October | 63°F (17°C) | 40°F (4°C) | 52°F (11°C) | 2.8" | 6.4 | 0.1 |
| November | 48°F (9°C) | 28°F (-2°C) | 38°F (3°C) | 2.2" | 19.7 | 0.0 |
| December | 35°F (2°C) | 18°F (-8°C) | 27°F (-3°C) | 1.5" | 28.6 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 85°F around July 14, short of 90°F on every date, while 149 dates carry a normal low at or below freezing, the coldest 11°F near January 21.
The freezing stretch
The normal low stays at or below 32°F into April 1, then returns to freezing around November 5, covering 149 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is June 2, when 40% of years recorded at least a hundredth of an inch. The driest is January 12 at 19%. Summed across the calendar, that is about 97 wet dates a year.
The widest day
September 22 carries the biggest normal gap between afternoon and dawn, 25°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Sigourney.
Monthly Precipitation
Average monthly rainfall
5.7 days with precipitation
6.4 days with precipitation
7.3 days with precipitation
9.4 days with precipitation
11.8 days with precipitation
11.6 days with precipitation
8.2 days with precipitation
8.8 days with precipitation
7.4 days with precipitation
7.6 days with precipitation
6.5 days with precipitation
5.9 days with precipitation
Sigourney runs a summer-peaked wet season
37% of Sigourney's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is June at 5.1", on a wide 52.9°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: June, May, August, taking 40% of the annual total between them.
- Driest month: January at 1.2".
- Winter share: 11% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
When it rains in Sigourney, it arrives in quantity
37.4" of precipitation falls across only about 97 wet days here, averaging 0.39 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 97 a year, 26% of all days
- Average depth per wet day
- 0.39 inches
- Most wet days
- May, about 12
- Fewest wet days
- January, about 6
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Frost Dates & Growing Season
First Fall Freeze
October 15
50% probability date
Last Spring Freeze
April 24
50% probability date
Growing Season
174 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,641
Higher = more heating needed
Cooling Degree Days
806
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IA closest to Sigourney on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (49°F here).
- Armour, SD 49°F · 0.0°F off
- Basin, WY 49°F · 0.0°F off
- Castle Dale, UT 49°F · 0.0°F off
- Colville, WA 49°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (37.4" here), excluding temperature-peer places.
- Beloit, WI 37.4" · 0.0" off
- Shabbona, IL 37.4" · 0.0" off
- Steuben, WI 37.4" · 0.0" off
- Bryan, OH 37.4" · 0.0" off
Data-derived climate profile
How Sigourney's climate pattern fits together
heating led · moderate · mid swing
Sigourney's energy balance leans toward cold weather: 6,641 annual heating degree days against 806 for cooling. Its 52.9°F seasonal range still makes the monthly rows more useful than the annual average alone.
Sigourney's frost-free season lasts about 174 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
July and January mark the typical warm and cold ends of the calendar in Sigourney's middle-range seasonal profile. The measured spread is 52.9°F. The annual average is 49°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Sigourney's 37.4 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Snowfall is not added to the interpretation because its annual value is missing. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Sigourney's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Sigourney, not an official NOAA class or a year-ahead forecast.
Questions about Sigourney's climate
How much rain does Sigourney get? ▼
How cold does Sigourney get in winter? ▼
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Sigourney's primary station: SIGOURNEY (USC00137678). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 1973110). Match rule for Sigourney: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Sigourney comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.