Castine, ME climate
Castine has cold, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 77°, a January night drops to 13°, and about 72 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Castine feels like
Winter
Spring
Summer
Fall
Castine weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 30° | 13° | 4.0" | 19.2" | 9 | 12° – 28° |
| February | 32° | 14° | 3.1" | 22.4" | 7 | 9° – 29° |
| March | 39° | 23° | 3.9" | 11.7" | 8 | 24° – 38° |
| April | 51° | 33° | 4.1" | 2.2" | 10 | 38° – 47° |
| May | 62° | 43° | 3.7" | 0 | 10 | 47° – 56° |
| June | 71° | 52° | 4.1" | 0 | 10 | 58° – 65° |
| July | 77° | 58° | 3.2" | 0 | 9 | 63° – 70° |
| August | 76° | 58° | 3.1" | 0 | 8 | 64° – 70° |
| September | 68° | 51° | 3.9" | 0 | 7 | 56° – 64° |
| October | 56° | 40° | 5.2" | 0.3" | 10 | 44° – 55° |
| November | 45° | 31° | 4.6" | 2.5" | 9 | 33° – 43° |
| December | 35° | 20° | 4.8" | 13.2" | 10 | 21° – 35° |
| Year | 53° | 36° | 47.6" | 71.5" | 105 |
“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 and snow in Castine
Castine gets 48 inches of rain and melted snow a year. October is the wettest month and August the driest. Rain or snow falls on about 105 days a year.
About 151 frost-free days a year
In half of years the last 32° night comes by May 7 and the first one by October 5. That leaves about 151 frost-free days for gardens, shorter than 80% of U.S. towns.
Heating and cooling a home in Castine
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Castine, 97% of that work is heating and 3% is cooling, so the furnace matters far more than the air conditioner.
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.
Castine and its neighbors
Castine borders 5 towns with climate data. January nights across them vary by 1.7°. Stockton Springs has the coldest January nights (11°) and Penobscot the hottest July afternoons (79°). Castine’s January low is 13° and its July high 77°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Castine compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Castine averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.5°). The shift is larger than in 81% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Castine’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 9° to 29°. August is the most reliable, staying within 6°.
Common questions about Castine’s climate
What is the coldest month in Castine?
January, with a typical high of 30° and a low of 13°.
What is the hottest month in Castine?
July, with a typical high of 77° and a low of 58°. About 2 days a year reach 90°.
How much snow does Castine get?
About 72 inches in a normal winter, most of it in February.
When is the first frost in Castine?
In half of years the first 32° night comes by October 5, and the last spring frost by May 7.
What is the rainiest month in Castine?
October, with 5.2 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Castine itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Belfast, ME (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.