Climate · Castleford

Castleford, ID climate

Castleford has chilly winters and warm summers, with very little rain. A typical July afternoon reaches 90°, a January night drops to 22°.

NOAA 1991-2020 climate normals Updated once a decade
July high
90°
51st hottest of 234 Idaho towns
January low
22°
110th mildest of 234 Idaho towns
Rain + melted snow
9 in
12th driest of 234 Idaho towns
A normal year

What a year in Castleford feels like

Winter

40° / 23°
Typical high / low · Snow is rare

Spring

61° / 36°
Typical high / low · Last frost around May 17

Summer

86° / 54°
Typical high / low · 34 days reach 90° in a normal year

Fall

64° / 37°
Typical high / low · First frost around Sep 29
Best months to be outsideMayJunSepHighs of 62–84° and lows of 40° or more
Month by month

Castleford weather by month

Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.

MonthHighLowRain + melt30-yr range
January39°22°0.9" 20° – 37°
February44°25°0.6" 26° – 42°
March54°30°0.9" 37° – 48°
April60°35°1.1" 43° – 52°
May70°42°1.3" 51° – 62°
June79°50°0.7" 60° – 73°
July90°57°0.2" 64° – 79°
August88°55°0.2" 66° – 75°
September78°47°0.5" 59° – 66°
October64°36°0.7" 41° – 57°
November49°27°0.7" 31° – 45°
December39°22°1.0" 25° – 36°
Year63°37°8.7"

“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.

Rain & snow

Rain and snow in Castleford

Castleford gets 9 inches of rain and melted snow a year. May is the wettest month and July the driest.

9 in
Rain + melted snow a year
Less rain than 99% of U.S. towns

Rain + melted snow by month

Inches of water
1.3"

Snowfall by month

No snow records from a nearby station.
Frost & the growing season

About 132 frost-free days a year

In half of years the last 32° night comes by May 17 and the first one by September 29. That leaves about 132 frost-free days for gardens, shorter than 94% of U.S. towns.

146
nights at or below 32° in a normal year
2
nights below 0° in a normal year
34
days that reach 90° in a normal year

Freezing nights by month

Average nights at or below 32°

90° days by month

Average days at 90° or more
Heating & cooling

Heating and cooling a home in Castleford

Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Castleford, 94% of that work is heating and 6% is cooling, so the furnace matters far more than the air conditioner.

94%heating
6,563 heating degree daysMore heating than 67% of U.S. towns
434 cooling degree daysLess cooling than 82% of U.S. towns

Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.

Compared with other towns

How Castleford compares

Summer heat90° July high
Hotter than 79% of U.S. towns51st hottest of 234 Idaho towns
Winter cold22° January low
Milder than 62% of U.S. towns110th mildest of 234 Idaho towns
Precipitation9" a year
Drier than 99% of U.S. towns12th driest of 234 Idaho towns
Growing season132 frost-free days
Shorter than 94% of U.S. towns108th shortest of 232 Idaho towns

Compared with every U.S. town and city on TownTapestry, each counted once.

Then and now

Warmer than it used to be

+1.2°1991–2020 average vs. the 20th century (1901–2000)

The last 30 years in Castleford averaged 1.2° warmer than the 1900s. The biggest change is in January (+2.9°). The shift is smaller than in 53% of U.S. towns.

❄️ Winter+1.7° now 32°, was 30°
🌷 Spring+0.9° now 49°, was 48°
☀️ Summer+1.3° now 70°, was 69°
🍂 Fall+0.8° now 50°, was 49°

Change by month1991–2020 average minus 1901–2000 average, at Castleford’s spot on NOAA’s grid

Year to year

How much a month can swing

A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from 20° to 37°. September is the most reliable, staying within 7°.

Coldest to warmest month in 30 yearsNormal
Questions

Common questions about Castleford’s climate

What is the coldest month in Castleford?

December, with a typical high of 39° and a low of 22°.

What is the hottest month in Castleford?

July, with a typical high of 90° and a low of 57°. About 34 days a year reach 90°.

When is the first frost in Castleford?

In half of years the first 32° night comes by September 29, and the last spring frost by May 17.

What is the rainiest month in Castleford?

May, with 1.3 inches of rain and melted snow. The year totals 9 inches.

Temperatures and rainfall come from NOAA’s gridded climate normals for Castleford itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Castleford 2 N, ID (2 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.

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