How extreme does Caldwell's weather get?

The hottest, coldest, wettest and snowiest days Caldwell 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 Boise Air Terminal station 38 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 Caldwell has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day

110°F Jul 13, 2002

That is about 17°F hotter than a normal July afternoon in Caldwell (typical high near 93°F).

The three most extreme on record

1 110°F Jul 13, 2002

2 110°F Jul 1, 2013

3 110°F Jun 28, 2015

❄️ Coldest night

-25°F Dec 22, 1990

About 50°F colder than a normal December night in Caldwell (typical low near 25°F).

The three most extreme on record

1 -25°F Dec 22, 1990

2 -23°F Dec 10, 1972

3 -23°F Dec 21, 1990

🌧️ Most rain in one day

1.77 in May 29, 1990

More rain in a single day than Caldwell usually gets in the whole month of May (typical May total about 1.5 in).

The three most extreme on record

1 1.77 in May 29, 1990

2 1.73 in Sep 11, 1976

3 1.61 in Aug 13, 1979

⛄ Most snow in one day

9.8 in Dec 20, 1996

Close to a whole typical December's snow in one day (Caldwell averages about 6 in across the month).

The three most extreme on record

1 9.8 in Dec 20, 1996

2 8.4 in Jan 20, 2002

3 6.8 in Jan 13, 2024

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

Caldwell's record heat sits well above even a hot day for the season — July's 110°F is about 17°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, Caldwell's warmest days reach the low 90s°F and its coldest nights drop to the mid-20s°F. But across the record it has gone as high as 110°F and as low as −25°F. A single day has delivered over 2 inches of rain or close to 10 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 Boise Air Terminal (NOAA GHCN station USW00024131), about 38 km from the city centre.

How we build these numbers →

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