Postville, IA Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from Postville's primary NOAA station, POSTVILLE.
The climate verdict for Postville
Winter sets the terms in Postville, Iowa. A pronounced 55.3°F seasonal swing and heating demand above twice the cooling total frame an annual average of 46°F. Its climate comfort score of 59/100 (moderate) lands mid-pack nationally, exceeding 37% of station-mapped location scores.
- 46°F
- annual average temperature (NOAA normal)
- 59/100
- comfort score, above 37% of station-mapped location scores
- 38.9"
- annual precipitation · 40" snow
- 155 days
- growing season, frost-free days
Postville: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00136766 · Postville, IA 46°F mean · 38.9" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 46°F
- RANK-COOL #1,578
- PHOTO-FINISH ≈ Eau Claire
- PRCP-MID 38.9"
- SWING-WIDE 55°F
- COMF-MID 59/100
- LOAD-HEAT 7,520 HDD
- STN-1 USC00136766
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Eau Claire, WI (+ 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.
- Postville (this station) 46°F
- Cold Alma Dam, WI 46°F
- Hot Deaver, WY 46°F
- Near Eau Claire, WI 46°F
- Near Elkader, IA 46°F
Climate Living Index · Postville
Postville: 39/100 · grade F
Postville publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Postville, not an official NOAA rating. Rankings still use Comfort Score 59/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 38.9 in · 3.9 from 35 in | 86/100 · A |
| Normal heat + freeze calendar | 164 calendar days | 36/100 · F |
| Frost-free season | 155 days/year | 29/100 · F |
| Snowfall burden | 39.8 inches/year | 28/100 · F |
| Annual temperature balance | 46.0°F · 21.5° from 67.5°F | 23/100 · F |
Postville · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Postville is a continental Köppen climate: Dfa
Coldest-month mean 16.6°F and warmest-month mean 71.9°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
- 71.9°F
- Coldest month
- 16.6°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 Postville sits across the climate record
Three NOAA fields for Postville's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 77%
- Among 6,861 stations, Postville sits in the cooler third of annual means.
- Annual precipitation
- 56th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Wider than 92%
- Warmest-to-coldest month gap for Postville is large versus 6,861 complete station-years.
How Postville compares across U.S. station-mapped locations
Postville's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
59 37th percentile score exceeds 37% 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%). This entry sits in this band.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 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
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 26°F (-4°C) | 7°F (-14°C) | 17°F (-9°C) | 1.1" | 12.0" | 30.7 | 0.0 |
| February | 30°F (-1°C) | 11°F (-12°C) | 20°F (-7°C) | 1.2" | 10.4" | 27.6 | 0.0 |
| March | 43°F (6°C) | 22°F (-5°C) | 33°F (0°C) | 2.1" | 5.0" | 25.1 | 0.0 |
| April | 58°F (14°C) | 34°F (1°C) | 46°F (8°C) | 4.1" | 1.6" | 12.8 | 0.0 |
| May | 69°F (21°C) | 47°F (8°C) | 58°F (15°C) | 5.0" | 0.0" | 1.6 | 0.5 |
| June | 79°F (26°C) | 58°F (14°C) | 68°F (20°C) | 5.9" | 0.0" | 0.0 | 2.2 |
| July | 83°F (28°C) | 61°F (16°C) | 72°F (22°C) | 4.5" | 0.0" | 0.0 | 4.1 |
| August | 81°F (27°C) | 58°F (15°C) | 70°F (21°C) | 4.4" | 0.0" | 0.0 | 1.8 |
| September | 74°F (23°C) | 49°F (10°C) | 62°F (16°C) | 4.0" | 0.0" | 0.6 | 0.6 |
| October | 61°F (16°C) | 37°F (3°C) | 49°F (9°C) | 3.0" | 0.1" | 10.3 | 0.0 |
| November | 45°F (7°C) | 26°F (-4°C) | 35°F (2°C) | 2.1" | 2.7" | 22.6 | 0.0 |
| December | 31°F (0°C) | 14°F (-10°C) | 23°F (-5°C) | 1.6" | 8.0" | 30.1 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 83°F around July 16, short of 90°F on every date, while 164 dates carry a normal low at or below freezing, the coldest 7°F near January 20.
The freezing stretch
The normal low stays at or below 32°F into April 10, then returns to freezing around October 30, covering 164 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 May 26, when 39% of years recorded at least a hundredth of an inch. The driest is January 2 at 19%. Summed across the calendar, that is about 97 wet dates a year.
The widest day
September 24 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 Postville.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 12.0"
5.8 days with precipitation
Snow: 10.4"
5.4 days with precipitation
Snow: 5.0"
6.7 days with precipitation
Snow: 1.6"
10.1 days with precipitation
12.2 days with precipitation
11.2 days with precipitation
8.8 days with precipitation
9.0 days with precipitation
8.5 days with precipitation
Snow: 0.1"
7.7 days with precipitation
Snow: 2.7"
5.9 days with precipitation
Snow: 8.0"
6.1 days with precipitation
Postville runs a summer-peaked wet season
38% of Postville'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 5.9", on a wide 55.3°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, July, taking 40% of the annual total between them.
- Driest month: January at 1.1".
- Winter share: 10% 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 Postville, it arrives in quantity
38.9" of precipitation falls across only about 97 wet days here, averaging 0.40 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, 27% of all days
- Average depth per wet day
- 0.40 inches
- Most wet days
- May, about 12
- Fewest wet days
- February, about 5
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.
Winter brings real snow to Postville
Postville averages 39.8 inches of snowfall a year, with January the snowiest month on the normals, spread across roughly 20 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 39.8 inches of depth.
- Days recording measurable snow: about 20 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 10% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 3
50% probability date
Last Spring Freeze
May 1
50% probability date
Growing Season
155 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,520
Higher = more heating needed
Cooling Degree Days
614
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IA closest to Postville 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 (46°F here).
- Arlington, WI 46°F · 0.0°F off
- Eau Claire, WI 46°F · 0.0°F off
- Glenbrook, NV 46°F · 0.0°F off
- Hillsboro, WI 46°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (38.9" here), excluding temperature-peer places.
- Galesburg, IL 39.0" · 0.0" off
- Baraboo, WI 38.9" · 0.0" off
- Hart, MI 38.9" · 0.0" off
- Ukiah, CA 38.9" · 0.0" off
Snow and freeze rhythm
When cold and snow define Postville
heating led · moderate · high swing
Winter and seasonal range jointly define this record. Postville logs 7,520 heating degree days, more than twice its 614 cooling total, while the typical coldest-to-warmest-month gap reaches 55.3°F. The annual mean therefore compresses two materially different seasons.
Postville's frost-free season lasts about 155 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Postville coldest normal
January
Averaging 17°F (-9°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Postville typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Postville snow peak
January
Postville averages 39.8 inches of snow a year, with January the snowiest month on the normals.
Questions about Postville's climate
How much snow does Postville get? ▼
How cold does Postville get in winter? ▼
How much energy does heating and cooling require in Postville? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Postville's primary station: POSTVILLE (USC00136766). 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 1964290). Match rule for Postville: 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 Postville 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.