Caribou, Maine climate: Normal weather by month, frost dates and records
Caribou's normal year runs from 3°F January nights to 77°F July afternoons, with 40.7 inches of precipitation and 118 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.8°C, January lows of −16°C, July highs of 25°C, 1,034 mm of precipitation a year.
- NOAA stationCaribou Weather Office
- Station IDUSW00014607
- Location46.87°N 68.02°W
- Elevation624 ft (190 m)
- Population7,328
On October 14, the normal high in Caribou is 54°F and the normal low 36°F, and the chance of measurable rain or snow is 44%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Caribou.
- Jan 21° 3°
- Feb 24° 4°
- Mar 34° 16°
- Apr 48° 29°
- May 63° 41°
- Jun 72° 51°
- Jul 77° 56°
- Aug 76° 54°
- Sep 67° 46°
- Oct 53° 36°
- Nov 40° 26°
- Dec 28° 12°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Caribou each month?
July is the warmest month, with normal highs of 77°F; January the coldest, with normal lows of 3°F. The most precipitation falls in July (4.23 in), the least in February (2.42 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 21°F | 3°F | 11.7°F | 2.95 | 25.0 | 14 | <1 | 30 | 8 h 50 min |
| February | 24°F | 4°F | 14.2°F | 2.42 | 25.3 | 12 | <1 | 28 | 10 h 20 min |
| March | 34°F | 16°F | 25.0°F | 2.77 | 21.4 | 13 | <1 | 29 | 11 h 50 min |
| April | 48°F | 29°F | 38.5°F | 2.99 | 8.3 | 13 | <1 | 21 | 13 h 30 min |
| May | 63°F | 41°F | 52.2°F | 3.46 | 0.8 | 15 | <1 | 4 | 15 h |
| June | 72°F | 51°F | 61.4°F | 3.89 | 0.0 | 14 | 1 | <1 | 15 h 50 min |
| July | 77°F | 56°F | 66.7°F | 4.23 | 0.0 | 14 | 1 | <1 | 15 h 30 min |
| August | 76°F | 54°F | 64.9°F | 3.61 | 0.0 | 13 | 1 | <1 | 14 h 20 min |
| September | 67°F | 46°F | 56.6°F | 3.44 | 0.1 | 12 | <1 | 2 | 12 h 40 min |
| October | 53°F | 36°F | 44.5°F | 3.99 | 1.7 | 14 | <1 | 12 | 11 h |
| November | 40°F | 26°F | 32.6°F | 3.35 | 10.4 | 13 | <1 | 24 | 9 h 30 min |
| December | 28°F | 12°F | 19.9°F | 3.60 | 25.2 | 15 | <1 | 30 | 8 h 30 min |
| Year (annual) | 50°F | 31°F | 40.7°F | 40.70 | 118.2 | 161 | 2 | 180 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −6°C | −16°C | −11.3°C | 75 mm | 64 cm |
| February | −4°C | −15°C | −9.9°C | 61 mm | 64 cm |
| March | 1°C | −9°C | −3.9°C | 70 mm | 54 cm |
| April | 9°C | −1°C | 3.6°C | 76 mm | 21 cm |
| May | 17°C | 5°C | 11.2°C | 88 mm | 2 cm |
| June | 22°C | 10°C | 16.3°C | 99 mm | 0 cm |
| July | 25°C | 13°C | 19.3°C | 107 mm | 0 cm |
| August | 24°C | 12°C | 18.3°C | 92 mm | 0 cm |
| September | 20°C | 8°C | 13.7°C | 87 mm | 0 cm |
| October | 12°C | 2°C | 6.9°C | 101 mm | 4 cm |
| November | 4°C | −4°C | 0.3°C | 85 mm | 26 cm |
| December | −2°C | −11°C | −6.7°C | 91 mm | 64 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014607; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Caribou?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, September has the fewest days with rain (12).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014607.
When is the last frost in Caribou?
In Caribou, the last spring frost (32°F) comes after May 7 in half of years and after May 24 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 17 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 71 year in 10 after May 24; 9 in 10 after April 27
- First autumn frost, half of years before
- October 11 year in 10 before September 17; 9 in 10 before October 14
NOAA puts the median frost-free season at 143 days, and the season without a hard freeze (28°F) at 167 days.
A hard freeze (28°F) comes after April 26 in half of springs and before October 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Caribou in zone 4a in ZIP code 04736. By the map's own method, the average of each year's coldest night over 1991-2020, Caribou's NOAA station is in zone 4b: the coldest night of a typical year reaches −23°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Maine · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00014607; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Caribou?
In a normal year in Caribou, 2 days a year reach 90°F, 180 nights fall to 32°F or colder and 161 days bring measurable precipitation.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 180a normal year
- Days that stay below freezing
- 91high of 32°F or less
- Days with 0.01 inch of precipitation
- 161a normal year
- Days with 1 inch of snow or more
- 30a normal year
The highest temperature in Caribou's official record (kept by the National Weather Service since 1939) is 96°F, on May 22, 1977; the lowest is −41°F, on February 1, 1955.
The wettest calendar year on that record is 2011, with 55.36 in; the snowiest season is 2007–08, with 197.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014607; records: ACIS (NOAA Regional Climate Centers), NWS threaded record CARthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Caribou, and how clear are its skies?
The summer (June-August) dew point averages 55°F. The muggiest month is July, with an average dew point of 57°F; the driest air comes in January (5°F). February is the windiest month (8.6 mph on average), and August has the most clear or nearly clear hours (55%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 5°F | 74% | 62% | 7.6 mph | 52% | 34% |
| February | 10°F | 70% | 57% | 8.6 mph | 47% | 40% |
| March | 21°F | 63% | 50% | 8.4 mph | 45% | 41% |
| April | 32°F | 60% | 42% | 8.0 mph | 45% | 38% |
| May | 44°F | 66% | 48% | 7.2 mph | 42% | 36% |
| June | 56°F | 72% | 54% | 6.3 mph | 44% | 29% |
| July | 57°F | 73% | 54% | 5.6 mph | 51% | 23% |
| August | 53°F | 74% | 54% | 6.2 mph | 55% | 25% |
| September | 43°F | 75% | 55% | 6.7 mph | 48% | 34% |
| October | 32°F | 76% | 63% | 7.9 mph | 35% | 51% |
| November | 21°F | 80% | 71% | 7.7 mph | 33% | 54% |
| December | 9°F | 77% | 68% | 8.0 mph | 41% | 47% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014607. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Caribou?
Over a year 67% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Caribou, 3.5 kWh per square metre a day. September is the sunniest month (73%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.4 |
| February | 66% | 2.3 |
| March | 68% | 3.5 |
| April | 67% | 4.6 |
| May | 65% | 5.1 |
| June | 67% | 5.6 |
| July | 72% | 5.6 |
| August | 73% | 4.9 |
| September | 73% | 3.9 |
| October | 63% | 2.3 |
| November | 58% | 1.4 |
| December | 56% | 1.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Caribou need?
A normal year in Caribou brings 9,048 heating degree days, 68% more than the median U.S. place (5,373), and 225 cooling degree days, 75% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,726 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,652 | 0 |
| February | 1,421 | 0 |
| March | 1,242 | 0 |
| April | 794 | 0 |
| May | 403 | 7 |
| June | 148 | 39 |
| July | 43 | 95 |
| August | 71 | 68 |
| September | 269 | 17 |
| October | 635 | 1 |
| November | 974 | 0 |
| December | 1,398 | 0 |
| Year (annual) | 9,048 | 225 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014607. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Caribou been warmer than normal lately?
2025 averaged 41.1°F, 0.4°F above the 1991-2020 normal of 40.7°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 43.4°F | +2.7°F | 37.03 | 106.0 |
| 2022 | 41.7°F | +1.0°F | 45.20 | 124.6 |
| 2023 | 43.2°F | +2.5°F | 41.85 | 120.2 |
| 2024 | 44.6°F | +3.9°F | 34.78 | 90.5 |
| 2025 | 41.1°F | +0.4°F | 39.03 | 118.6 |
Over 82 complete years from 1941 to 2025, the station's annual mean temperature rose at a fitted 4.4°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00014607; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Caribou's climate compare?
Caribou is warmer than 5 of the other 41 places with their own NOAA record in Maine, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 40.7°F is warmer than 7%.
In the Köppen classification computed from these normals, Caribou is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Caribou share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Fort Fairfield, ME3,293 people · 11 mi SE
- Washburn, ME1,510 people · 8 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Caribou's climate
What is the coldest month in Caribou?
January, with a normal high of 21°F and a normal low of 3°F. The warmest is July (77°F by day, 56°F at night).
Does it snow in Caribou?
Yes: 118 inches in a normal year, falling on 63 days with 0.1 inch or more, the most in February (25.3 inches).
What is the rainiest month in Caribou?
July, with 4.23 in of precipitation in a normal year; the driest is February with 2.42 in.
What plant hardiness zone is Caribou in?
The USDA's 2023 map puts Caribou in zone 4a in ZIP code 04736. By the same method at Caribou's NOAA station, the coldest night of a typical year reaches −23°F (30 years, 1991-2020): zone 4b.
How late can frost come in Caribou?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 24. Waiting until May 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Caribou in OctoberThis month day by day, its records and recent years
- Maine climateThe statewide normals and every place in the state
- Limestone, ME9 miles from this station, 38.6°F a year
- Presque Isle, ME15 miles from this station, 41.6°F a year
- Van Buren, ME21 miles from this station, 38.4°F a year
- Bridgewater, ME32 miles from this station, 40.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made