Iowa

Mediapolis, Iowa Climate

NOAA 1991-2020 normals for Gladstone Dam 18, 18.3 km from Mediapolis

The warmest month is July, with an average high of 86°F; the coldest is January, with an average low of 16°F. A normal year brings 37.2 in of precipitation and 16.9 in of snow.

Temperature through the year

The normal daily high and low and the record for every date at Burlington (BRL), since 1964. The line marks today.

Normal daily high and low temperature at Mediapolis through the year, in °F, with the record for each date.-50050100150JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 24

Normal high
75°F
Normal low
53°F
Record high
95°Fin 2017
Record low
35°Fin 1989
Chance of a wet day
24%
Daylight
12 h 04 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysSnowfallFreeze nightsHeating DDCooling DD
January32°F16°F70°F (1989)-23°F (1977)1.39 in7.14.9 in28.91,2690
February37°F20°F76°F (2024)-26°F (1996)1.69 in7.26.3 in25.11,0290
March49°F30°F88°F (1986)-9°F (2014)2.35 in8.41.8 in19.47882
April62°F42°F92°F (1986)11°F (1982)3.77 in10.20.3 in4.43979
May73°F53°F98°F (2018)28°F (2002)5.02 in11.90.0 in0.113872
June82°F63°F104°F (1988)40°F (1977)4.66 in10.40.0 in0.015242
July86°F67°F105°F (2012)46°F (1971)4.03 in8.80.0 in0.01348
August84°F65°F105°F (1983)42°F (1986)3.60 in8.70.0 in0.03291
September78°F56°F101°F (2000)30°F (1984)3.62 in7.20.0 in0.170127
October65°F45°F93°F (2006)18°F (1972)2.80 in7.90.1 in2.333817
November50°F33°F79°F (2000)-2°F (1977)2.45 in7.80.3 in15.27140
December37°F22°F74°F (2021)-20°F (1989)1.81 in7.33.2 in26.61,0930
Year61°F43°F37.19 in10316.9 in1225,8531,108

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

37.2 in in a normal year, most in May.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Mediapolis, in percent, and of at least 0.1 inch of snowfall.010203040JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day
  • Chance of snowfall

Snow

NOAA 1991-2020 snowfall normals for Gladstone Dam 18.

16.9 in of snow in a normal year.

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gladstone Dam 18. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 8 and the first fall freeze around October 29, a growing season of about 202 days.

Median at 36°F
last April 20, first October 19
Median at 32°F
last April 8, first October 29
Median at 28°F
last March 31, first November 7

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Mediapolis.

The muggiest month is July, when 55 percent of days are muggy or worse, with a mean dew point of 65°F or more.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January18°F85%100%0%0%0%0%0%
February22°F81%100%0%0%0%0%0%
March31°F77%97%2%1%0%0%0%
April42°F73%88%8%4%0%0%0%
May53°F75%55%16%16%12%2%0%
June63°F75%17%19%21%24%17%2%
July65°F72%7%17%21%26%24%5%
August63°F70%16%22%23%22%14%3%
September54°F69%52%20%14%11%4%0%
October43°F72%86%9%3%2%0%0%
November32°F78%98%2%0%0%0%0%
December23°F85%100%0%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is September, with the sky 48 percent covered on average; the cloudiest is December, at 67 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is April, averaging 12.3 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 17, with 15 h 08 min of daylight; the shortest is Dec 18, with 9 h 13 min.

Hours of daylight at Mediapolis through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Des Moines County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Des Moines County: 74.0°F (+0.9 °F against 1991-2020), the 48th warmest in 132 years on record.

August 2026 in Des Moines County: 8.38 in (+4.56 in against 1991-2020), the 5th wettest in 132 years on record.

January to August 2026 in Des Moines County: 55.6°F (+2.5 °F against 1991-2020), the 6th warmest in 132 years on record.

January to August 2026 in Des Moines County: 31.09 in (+3.71 in against 1991-2020), the 22nd wettest in 132 years on record.

Warmest August
81.6°F in 1947
Coolest August
67.3°F in 1915
Wettest August
10.18 in in 1980
Driest August
0.16 in in 2013

Every year since 1895

Each year's average temperature in Des Moines County against the 1991-2020 average, in °F, 1895 to 2025.-4-20+2+41900192019401960198020002020NOAA NCEI Climate at a Glance

Iowa climate and rankings

Month pages

The weather in Mediapolis in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 1964. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00113455 (Gladstone Dam 18), public domain. Records: NOAA GHCN-Daily, station USC00131060, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.