How extreme does Waterloo's weather get?

The hottest, coldest, wettest and snowiest days Waterloo has recorded — the outer limits of what its weather can do, and how far they sit beyond a normal day.

Based on 50+ years of daily weather observations (1971–present), from the Waterloo Muni Ap station 8 km away. Updated through May 2026 — an all-time extreme only changes when a more extreme day actually occurs, so some dates are old. That is normal, not stale data.

The four kinds of extreme

The hottest, coldest, wettest and snowiest single days Waterloo has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day

105°F Jul 31, 1988

That is about 20°F hotter than a normal July afternoon in Waterloo (typical high near 85°F).

The three most extreme on record

1 105°F Jul 31, 1988

2 105°F Aug 17, 1988

3 105°F Aug 23, 2023

❄️ Coldest night

-34°F Jan 16, 2009

About 45°F colder than a normal January night in Waterloo (typical low near 11°F).

The three most extreme on record

1 -34°F Jan 16, 2009

2 -33°F Jan 20, 1994

3 -31°F Feb 2, 1996

🌧️ Most rain in one day

5.49 in Jul 2, 1999

More rain in a single day than Waterloo usually gets in the whole month of July (typical July total about 4.3 in).

The three most extreme on record

1 5.49 in Jul 2, 1999

2 4.35 in Jun 15, 1980

3 4.10 in Aug 28, 2015

⛄ Most snow in one day

13.2 in Jan 3, 1971

Close to a whole typical January's snow in one day (Waterloo averages about 10 in across the month).

The three most extreme on record

1 13.2 in Jan 3, 1971

2 10.5 in Nov 20, 2015

3 10.4 in Dec 1, 1985

How hot and cold it gets, month by month

The shaded band is the normal range of daily temperatures for each month. The dots show the most extreme it has ever been — so you can see how far beyond a normal day the records really sit.

normal range of daily temperatureshottest ever recordedcoldest ever recorded

Waterloo's record heat sits well above even a hot day for the season — July's 105°F is about 20°F beyond a normal hot afternoon. Its record cold is just as far below a normal winter night — the dots mark how rare each extreme really is.

In plain terms

In a normal year, Waterloo's warmest days reach the mid-80s°F and its coldest nights drop to the low 10s°F. But across the record it has gone as high as 105°F and as low as −34°F. A single day has delivered over 5 inches of rain or close to 13 inches of snow. Those are the outer edges worth knowing if you are moving here, planning a trip, or thinking about a house.

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Waterloo Muni AP (NOAA GHCN station USW00094910), about 8 km from the city centre.

How we build these numbers →

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