Bangor, Maine climate: Normal weather by month, frost dates and records
Bangor's normal year runs from 9°F January nights to 80°F July afternoons, with 41.7 inches of precipitation and 75 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.2°C, January lows of −13°C, July highs of 27°C, 1,059 mm of precipitation a year.
- NOAA stationBangor International Airport
- Station IDUSW00014606
- Location44.80°N 68.82°W
- Elevation148 ft (45 m)
- Population32,446
On October 22, the normal high in Bangor is 56°F and the normal low 36°F, and the chance of measurable rain or snow is 37%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Bangor.
- Jan 28° 9°
- Feb 31° 11°
- Mar 40° 21°
- Apr 53° 32°
- May 66° 43°
- Jun 75° 53°
- Jul 80° 59°
- Aug 79° 57°
- Sep 71° 49°
- Oct 58° 38°
- Nov 46° 29°
- Dec 35° 17°
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 Bangor each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 9°F. The most precipitation falls in October (4.58 in), the least in February (2.38 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 | 28°F | 9°F | 18.5°F | 3.17 | 18.6 | 11 | <1 | 30 | 9 h 10 min |
| February | 31°F | 11°F | 21.0°F | 2.38 | 17.5 | 10 | <1 | 27 | 10 h 20 min |
| March | 40°F | 21°F | 30.6°F | 3.22 | 15.2 | 11 | <1 | 27 | 11 h 50 min |
| April | 53°F | 32°F | 42.8°F | 3.61 | 3.7 | 12 | <1 | 16 | 13 h 30 min |
| May | 66°F | 43°F | 54.5°F | 3.34 | 0.0 | 12 | <1 | 2 | 14 h 50 min |
| June | 75°F | 53°F | 63.6°F | 3.87 | 0.0 | 12 | 2 | <1 | 15 h 30 min |
| July | 80°F | 59°F | 69.5°F | 3.16 | 0.0 | 11 | 2 | <1 | 15 h 20 min |
| August | 79°F | 57°F | 68.2°F | 3.06 | 0.0 | 10 | 2 | <1 | 14 h 10 min |
| September | 71°F | 49°F | 59.9°F | 3.76 | 0.0 | 9 | <1 | 1 | 12 h 40 min |
| October | 58°F | 38°F | 48.2°F | 4.58 | 0.6 | 11 | <1 | 9 | 11 h |
| November | 46°F | 29°F | 37.3°F | 3.84 | 4.3 | 11 | <1 | 21 | 9 h 40 min |
| December | 35°F | 17°F | 25.9°F | 3.72 | 14.7 | 13 | <1 | 29 | 8 h 50 min |
| Year (annual) | 55°F | 35°F | 45.0°F | 41.71 | 74.6 | 134 | 6 | 161 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −13°C | −7.5°C | 81 mm | 47 cm |
| February | 0°C | −12°C | −6.1°C | 60 mm | 44 cm |
| March | 5°C | −6°C | −0.8°C | 82 mm | 39 cm |
| April | 12°C | 0°C | 6.0°C | 92 mm | 9 cm |
| May | 19°C | 6°C | 12.5°C | 85 mm | 0 cm |
| June | 24°C | 11°C | 17.6°C | 98 mm | 0 cm |
| July | 27°C | 15°C | 20.8°C | 80 mm | 0 cm |
| August | 26°C | 14°C | 20.1°C | 78 mm | 0 cm |
| September | 22°C | 9°C | 15.5°C | 96 mm | 0 cm |
| October | 15°C | 3°C | 9.0°C | 116 mm | 2 cm |
| November | 8°C | −2°C | 2.9°C | 98 mm | 11 cm |
| December | 1°C | −8°C | −3.4°C | 94 mm | 37 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014606; 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 Bangor?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (9).
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 USW00014606.
When is the last frost in Bangor?
In Bangor, the last spring frost (32°F) comes after May 4 in half of years and after May 17 in one year in ten; the first autumn frost comes before October 4 in half of years and before September 23 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 41 year in 10 after May 17; 9 in 10 after April 24
- First autumn frost, half of years before
- October 41 year in 10 before September 23; 9 in 10 before October 21
NOAA puts the median frost-free season at 152 days, and the season without a hard freeze (28°F) at 175 days.
A hard freeze (28°F) comes after April 23 in half of springs and before October 17 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Bangor in zone 5a in ZIP code 04401. By the map's own method, the average of each year's coldest night over 1991-2020, Bangor's NOAA station is in zone 5a: the coldest night of a typical year reaches −17°F (30 complete years).
Frost dates for every NOAA station in Maine · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00014606; 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 Bangor?
In a normal year in Bangor, 6 days a year reach 90°F, 161 nights fall to 32°F or colder and 134 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 161a normal year
- Days that stay below freezing
- 55high of 32°F or less
- Days with 0.01 inch of precipitation
- 134a normal year
- Days with 1 inch of snow or more
- 21a normal year
The highest temperature in Bangor's official record (kept by the National Weather Service since 1925) is 104°F, on August 19, 1935; the lowest is −32°F, on February 10, 1948.
The wettest calendar year on that record is 1983, with 65.24 in; the snowiest season is 1962–63, with 181.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014606; records: ACIS (NOAA Regional Climate Centers), NWS threaded record BGRthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Bangor?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Bangor, 3.7 kWh per square metre a day. September is the sunniest month (77%) and December the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 1.6 |
| February | 67% | 2.4 |
| March | 69% | 3.6 |
| April | 67% | 4.6 |
| May | 67% | 5.3 |
| June | 69% | 5.6 |
| July | 75% | 5.8 |
| August | 77% | 5.2 |
| September | 77% | 4.2 |
| October | 69% | 2.7 |
| November | 65% | 1.7 |
| December | 61% | 1.3 |
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 Bangor need?
A normal year in Bangor brings 7,626 heating degree days, 42% more than the median U.S. place (5,373), and 379 cooling degree days, 58% 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 2,155 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,440 | 0 |
| February | 1,231 | 0 |
| March | 1,066 | 0 |
| April | 666 | 0 |
| May | 333 | 7 |
| June | 98 | 58 |
| July | 16 | 156 |
| August | 26 | 125 |
| September | 186 | 32 |
| October | 522 | 1 |
| November | 831 | 0 |
| December | 1,212 | 0 |
| Year (annual) | 7,626 | 379 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014606. 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 Bangor been warmer than normal lately?
2025 averaged 44.7°F, 0.3°F below the 1991-2020 normal of 45.0°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 47.2°F | +2.2°F | 40.85 | 38.0 |
| 2022 | 46.7°F | +1.7°F | 48.38 | 65.1 |
| 2023 | 47.4°F | +2.4°F | 49.28 | 69.6 |
| 2024 | 47.7°F | +2.7°F | 41.78 | 52.6 |
| 2025 | 44.7°F | −0.3°F | 36.08 | 62.8 |
Over 67 complete years from 1956 to 2025, the station's annual mean temperature rose at a fitted 6.1°F per century (+0.34°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00014606; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Bangor's climate compare?
Bangor is warmer than 26 of the other 41 places with their own NOAA record in Maine, and wetter than 5. Across the 7,247 U.S. stations with normals, its annual mean of 45.0°F is warmer than 19%.
In the Köppen classification computed from these normals, Bangor 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 Bangor share this climate record?
4 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.
- Brewer, ME9,629 people · 4 mi E
- Hampden, ME8,022 people · 4 mi S
- Bucksport, ME5,039 people · 14 mi S
- Winterport, ME3,865 people · 11 mi S
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 Bangor's climate
What is the coldest month in Bangor?
January, with a normal high of 28°F and a normal low of 9°F. The warmest is July (80°F by day, 59°F at night).
Does it snow in Bangor?
Yes: 75 inches in a normal year, falling on 31 days with 0.1 inch or more, the most in January (18.6 inches).
What is the rainiest month in Bangor?
October, with 4.58 in of precipitation in a normal year; the driest is February with 2.38 in.
What plant hardiness zone is Bangor in?
The USDA's 2023 map puts Bangor in zone 5a in ZIP code 04401. By the same method at Bangor's NOAA station, the coldest night of a typical year reaches −17°F (30 years, 1991-2020): zone 5a.
How late can frost come in Bangor?
In half of years the last 32°F night comes after May 4; in one year in ten it comes after May 17. Waiting until May 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Bangor in OctoberThis month day by day, its records and recent years
- Maine climateThe statewide normals and every place in the state
- Orono, ME10 miles from this station, 45.1°F a year
- Old, ME11 miles from this station, 43.2°F a year
- Corinna, ME22 miles from this station, 44.5°F a year
- East Surry, ME27 miles from this station, 44.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made