PlainClimate
NOAA 1991–2020 normals 50°F annual avg Public-domain federal data

Allerton, IA Climate

Temperature, precipitation, and comfort score from NOAA NCEI 1991–2020 normals →

50°F
Avg annual temp
68/100
Comfort score
40.4"
Annual precip
181d
Growing season

30-year climate normals from 1 weather station (1991-2020).

The climate verdict for Allerton

Allerton, Iowa averages 50°F a year and scores 68/100 on the comfort index - good, milder than 58% of U.S. cities.

50°F
annual average temperature (NOAA normal)
68/100
comfort score, milder than 58% of U.S. cities
40.4"
precipitation, annual total
181 days
frost-free growing season

Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.

Avg Temperature

50°F (10°C)

Avg High

60°F

Avg Low

40°F

Annual Precip

40.4"

Comfort Score

68/100

Good

Climate Comfort Score

68/100

Good

Avg Annual Temperature

50°F

30-year mean (NOAA NCEI)

Annual Precipitation

40.4"

Liquid-equivalent total

Comfort score vs national 100-point ceiling (Allerton) 68.0%
National median (63)

PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Good for the Allerton area.

How Allerton compares to every U.S. city

Allerton's comfort score vs. all U.S. cities

PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals

68 Top 42% higher than 58% of 6,915 US cities

0–10: 0 US cities (0%). Below this entry. 10–20: 0 US cities (0%). Below this entry. 20–30: 58 US cities (1%). Below this entry. 30–40: 439 US cities (6%). Below this entry. 40–50: 1,302 US cities (19%). Below this entry. 50–60: 1,433 US cities (21%). Below this entry. 60–70: 1,357 US cities (20%). This entry sits in this band. 70–80: 1,102 US cities (16%). Above this entry. 80–90: 778 US cities (11%). Above this entry. 90–100: 420 US cities (6%). Above this entry. This city 0 100 every U.S. city, bucketed by value

Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020

Warming context for Allerton

Methodology

Since 1900, U.S. land temperatures have tracked (and diverged from) the global mean - the chart below shows how. Allerton's current NOAA 1991-2020 normal sits within that longer spread, and the most recent decade runs warmer than the 30-year mean.

Warming context, U.S. vs global, with Paris reference lines Anomaly chart from 1900 to 2024. Local series shows warming of 0.11 °C per decade versus a global rate of 0.11 °C per decade (ratio 1.00). Paris Agreement thresholds at 1.5 and 2.0 °C are dashed. -1.0°C -0.5°C +0.0°C +0.5°C +1.0°C +1.5°C +2.0°C +2.5°C Paris 1.5°C Paris 2.0°C 1900192019401960198020002020
  • United States land mean (NOAA NCEI) +0.11 °C/decade
  • Global anomaly (NASA GISTEMP) +0.11 °C/decade
  • Paris Agreement thresholds 1.5°C / 2.0°C
Sources: NOAA NCEI, NASA GISTEMP. Paris thresholds per IPCC AR6 WG1.

Monthly Temperatures

Average daily high and low temperatures by month

Month Avg High Avg Low Mean
January 32°F (0°C) 13°F (-11°C) 22°F (-5°C)
February 37°F (3°C) 17°F (-9°C) 27°F (-3°C)
March 49°F (10°C) 28°F (-2°C) 38°F (4°C)
April 62°F (16°C) 38°F (3°C) 50°F (10°C)
May 71°F (22°C) 50°F (10°C) 61°F (16°C)
June 80°F (27°C) 60°F (16°C) 70°F (21°C)
July 85°F (29°C) 64°F (18°C) 75°F (24°C)
August 83°F (28°C) 62°F (17°C) 73°F (23°C)
September 76°F (24°C) 54°F (12°C) 65°F (18°C)
October 64°F (18°C) 41°F (5°C) 53°F (11°C)
November 49°F (9°C) 28°F (-2°C) 39°F (4°C)
December 37°F (3°C) 19°F (-7°C) 28°F (-2°C)

Monthly Precipitation

Average monthly rainfall

January 1.1"
February 1.5"
March 2.4"
April 4.0"
May 5.7"
June 5.1"
July 4.7"
August 4.9"
September 4.2"
October 3.1"
November 2.1"
December 1.6"

Frost Dates & Growing Season

First Fall Freeze

October 19

50% probability date

Last Spring Freeze

April 21

50% probability date

Growing Season

181 days

Heating & Cooling Degree Days

Annual totals indicate energy demand for heating and cooling

Heating Degree Days

6,363

Higher = more heating needed

Cooling Degree Days

874

Higher = more cooling needed

Warmest Month

July

Coldest Month

January

What Allerton's climate means for you

Allerton runs 50°F a year - peaking in July, coldest in January.

  • Gardeners get about 181 frost-free days, with the last spring freeze near April 21 - plan the planting calendar around it, not the regional average.
  • Energy bills track 6,363 heating and 874 cooling degree days a year, higher means the furnace or AC runs more.
  • Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings

These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.

Climate Guides

Climate Insight: Allerton, IA

Allerton, Iowa runs an annual average of 50°F, ranging from a mean daily high of 60°F to a mean daily low of 40°F, per NOAA's 1991–2020 climate normals. July is typically the warmest month of the year, while January is the coldest. Drawn from station USC00130149, these thirty-year averages smooth out year-to-year swings into a baseline for what a typical month looks like here.

Allerton averages 40.4 inches of precipitation a year, predominantly as rainfall, and that matters as much to daily life here as temperature does. The frost-free season averages 181 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 21 and the first fall freeze near October 19. As for energy demand, 6,363 heating degree days and 874 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Allerton scores 68/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above are the practical planning tool: mild highs and lows land in the shoulder seasons, July-driven heat peaks in summer, and January-driven cold sets in over deep winter. These are thirty-year averages, not a forecast - any single year can run warmer, wetter, drier, or cooler than the normal.

Frequently Asked Questions

What is the average temperature in Allerton, IA?
The average annual temperature in Allerton, Iowa is 50°F. The warmest month averages 85°F (29°C) and the coldest averages 13°F (-11°C).
How much rain does Allerton get?
Allerton receives 40.4 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Allerton?
Allerton has a climate comfort score of 68/100 (Good), milder than 58% of U.S. cities in the PlainClimate database.
When is the growing season in Allerton?
Allerton has approximately 181 frost-free days per year, with the last spring freeze around April 21 and the first fall freeze around October 19.
How much energy does heating and cooling require in Allerton?
Allerton has 6,363 heating degree days and 874 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Allerton climate data come from?
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00130149 near Allerton.

Data Sources

Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00130149. For informational purposes only.

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial

Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.