ClimateAverages

Waterloo Climate

Iowa, United States of America · population 68,460 · 295 weather stations within 200 km · records 1819 to 2025

Average annual daytime high
14.4°C
Warmest month · July
28.9°C
Typical daytime high
Coldest month · January
-13.9°C
Typical overnight low

Waterloo has an average annual daytime high of 14.4°C, based on the 1951 to 1980 baseline. Its warmest month is July, when highs typically reach 28.9°C, and its coldest is January, with overnight lows near -13.9°C.

Month by month averages

MonthAvg highAvg low
January-3.6°C-13.9°CColdest
February-0.2°C-10.7°C
March5.8°C-4.8°C
April15.4°C2.6°C
May22.1°C9.0°C
June26.9°C14.2°C
July28.9°C16.4°CWarmest
August28.0°C15.3°C
September23.8°C10.3°C
October17.4°C4.1°C
November7.8°C-3.0°C
December-0.1°C-9.6°C

Temperature range across the year

-16°-4°8°19°31°JanFebMarAprMayJunJulAugSepOctNovDec
Daytime high Overnight low
Hottest year on record
2011
+3.1°C vs. 1951–1980
Coldest year on record
1842
-3.4°C vs. 1951–1980

These figures reflect annual averages, not single-day records. Daily observations are outside this dataset's precision.

Is Waterloo getting hotter?

Since 1900, Waterloo's average temperature has risen by +2.2°C. Compared to the earliest station records that begin in 1819, warming totals +2.2°C.

7.7°8.4°9.1°9.8°10.4°1951–1980 baseline190019251950197520002025

20-year smoothed annual temperature reconstructed from station anomalies. Dashed line: 1951–1980 baseline.

Best time to visit
April to October

Daytime highs sit within a comfortable 15°C to 26°C range.

FAQ

What is the average temperature in Waterloo?

Waterloo's average annual daytime high is 14.4°C, based on the 1951 to 1980 baseline period. The warmest month is July, with highs averaging 28.9°C, and the coldest is January, with lows averaging -13.9°C.

What is the warmest month in Waterloo?

July is the warmest month in Waterloo, with typical daytime highs of 28.9°C.

What is the hottest year on record for Waterloo?

2011 is the hottest year on record for Waterloo, running +3.1°C above the 1951 to 1980 baseline.

Is Waterloo getting hotter?

Yes. Since 1900, Waterloo has warmed by roughly +2.2°C.

When is the best time to visit Waterloo?

April to October typically offers the most comfortable daytime highs, in the 15°C to 26°C range.

Nearby cities

Baseline period 1951 to 1980. Monthly averages are the mean of station observations weighted by proximity. Warming trend is the 20-year smoothed anomaly against that baseline.