Newcastle, Maine climate: Normal weather by month, frost dates and records
Newcastle's normal year runs from 15°F January nights to 78°F July afternoons, with 49.3 inches of precipitation and 79 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.0°C, January lows of −10°C, July highs of 26°C, 1,251 mm of precipitation a year.
- NOAA stationNewcastle
- Station IDUSC00175675
- Location44.04°N 69.54°W
- Elevation213 ft (65 m)
- From the centerunder 1 mile
- Population (town)1,900
- Census place621
On October 23, the normal high in Newcastle is 54°F and the normal low 40°F, and the chance of measurable rain or snow is 40%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Newcastle.
- Jan 30° 15°
- Feb 33° 17°
- Mar 41° 25°
- Apr 54° 35°
- May 65° 45°
- Jun 73° 54°
- Jul 78° 60°
- Aug 77° 59°
- Sep 69° 52°
- Oct 57° 42°
- Nov 46° 32°
- Dec 36° 22°
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 Newcastle each month?
July is the warmest month, with normal highs of 78°F; January the coldest, with normal lows of 15°F. The most precipitation falls in October (4.97 in), the least in August (3.35 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 30°F | 15°F | 22.4°F | 3.83 | 19.6 | 12 | <1 | 30 | 9 h 10 min |
| February | 33°F | 17°F | 25.0°F | 3.61 | 20.3 | 11 | <1 | 26 | 10 h 30 min |
| March | 41°F | 25°F | 32.9°F | 4.32 | 14.1 | 11 | <1 | 26 | 11 h 50 min |
| April | 54°F | 35°F | 44.2°F | 4.17 | 4.4 | 12 | <1 | 12 | 13 h 20 min |
| May | 65°F | 45°F | 54.8°F | 3.80 | 0.0 | 14 | <1 | <1 | 14 h 40 min |
| June | 73°F | 54°F | 63.3°F | 4.28 | 0.0 | 13 | <1 | <1 | 15 h 30 min |
| July | 78°F | 60°F | 69.1°F | 3.42 | 0.0 | 12 | 1 | <1 | 15 h 10 min |
| August | 77°F | 59°F | 68.1°F | 3.35 | 0.0 | 10 | <1 | <1 | 14 h |
| September | 69°F | 52°F | 60.6°F | 4.19 | 0.0 | 10 | <1 | <1 | 12 h 40 min |
| October | 57°F | 42°F | 49.4°F | 4.97 | 0.3 | 12 | <1 | 4 | 11 h 10 min |
| November | 46°F | 32°F | 39.0°F | 4.57 | 3.5 | 12 | <1 | 17 | 9 h 40 min |
| December | 36°F | 22°F | 28.7°F | 4.74 | 16.5 | 13 | <1 | 27 | 8 h 50 min |
| Year (annual) | 55°F | 38°F | 46.4°F | 49.25 | 78.7 | 142 | 2 | 142 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −10°C | −5.3°C | 97 mm | 50 cm |
| February | 1°C | −8°C | −3.9°C | 92 mm | 52 cm |
| March | 5°C | −4°C | 0.5°C | 110 mm | 36 cm |
| April | 12°C | 2°C | 6.8°C | 106 mm | 11 cm |
| May | 18°C | 7°C | 12.7°C | 97 mm | 0 cm |
| June | 23°C | 12°C | 17.4°C | 109 mm | 0 cm |
| July | 26°C | 15°C | 20.6°C | 87 mm | 0 cm |
| August | 25°C | 15°C | 20.1°C | 85 mm | 0 cm |
| September | 21°C | 11°C | 15.9°C | 106 mm | 0 cm |
| October | 14°C | 5°C | 9.7°C | 126 mm | 1 cm |
| November | 8°C | 0°C | 3.9°C | 116 mm | 9 cm |
| December | 2°C | −6°C | −1.8°C | 120 mm | 42 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00175675; 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 Newcastle?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, August has the fewest days with rain (10).
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 USC00175675.
When is the last frost in Newcastle?
In Newcastle, the last spring frost (32°F) comes after April 27 in half of years and after May 10 in one year in ten; the first autumn frost comes before October 18 in half of years and before October 3 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
- April 271 year in 10 after May 10; 9 in 10 after April 16
- First autumn frost, half of years before
- October 181 year in 10 before October 3; 9 in 10 before November 2
NOAA puts the median frost-free season at 172 days, and the season without a hard freeze (28°F) at 199 days.
A hard freeze (28°F) comes after April 14 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Newcastle in zone 5b in ZIP code 04553, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Newcastle's NOAA station is in zone 6a: the coldest night of a typical year reaches −9°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 USC00175675; 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 Newcastle?
In a normal year in Newcastle, 2 days a year reach 90°F, 142 nights fall to 32°F or colder and 142 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
- 142a normal year
- Days that stay below freezing
- 51high of 32°F or less
- Days with 0.01 inch of precipitation
- 142a normal year
- Days with 1 inch of snow or more
- 20a normal year
The highest temperature in this station's record (since 1965) is 101°F, on August 2, 1975; the lowest is −24°F, on February 4, 2023.
The wettest calendar year on that record is 2005, with 71.56 in; the snowiest season is 1970–71, with 139.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00175675; records: ACIS (NOAA Regional Climate Centers), station USC00175675. Records use complete months only; a month missing more than three days is left out.
How sunny is Newcastle?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Newcastle, 3.7 kWh per square metre a day. September is the sunniest month (77%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.7 |
| February | 69% | 2.5 |
| March | 70% | 3.7 |
| April | 68% | 4.6 |
| May | 67% | 5.3 |
| June | 68% | 5.6 |
| July | 75% | 5.8 |
| August | 77% | 5.3 |
| September | 77% | 4.2 |
| October | 68% | 2.6 |
| November | 66% | 1.7 |
| December | 62% | 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 Newcastle need?
A normal year in Newcastle brings 7,077 heating degree days, 32% more than the median U.S. place (5,373), and 346 cooling degree days, 62% 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 2,166 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,321 | 0 |
| February | 1,121 | 0 |
| March | 995 | 0 |
| April | 626 | 0 |
| May | 326 | 8 |
| June | 99 | 50 |
| July | 15 | 140 |
| August | 21 | 117 |
| September | 162 | 30 |
| October | 484 | 1 |
| November | 782 | 0 |
| December | 1,125 | 0 |
| Year (annual) | 7,077 | 346 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00175675. 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 Newcastle been warmer than normal lately?
2024 averaged 48.6°F, 2.2°F above the 1991-2020 normal of 46.4°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 48.5°F | +2.1°F | 43.69 | 33.4 |
| 2022 | 48.0°F | +1.6°F | 45.87 | 45.0 |
| 2023 | 48.4°F | +2.0°F | 57.45 | 76.9 |
| 2024 | 48.6°F | +2.2°F | 49.40 | 56.2 |
Over 58 complete years from 1966 to 2024, the station's annual mean temperature rose at a fitted 5.0°F per century (+0.28°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00175675; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Newcastle's climate compare?
Newcastle is warmer than 38 of the other 41 places with their own NOAA record in Maine, and wetter than 31. Across the 7,247 U.S. stations with normals, its annual mean of 46.4°F is warmer than 25%.
In the Köppen classification computed from these normals, Newcastle 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 Newcastle 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.
- Waldoboro, ME5,296 people · 9 mi NE
- Damariscotta, ME2,307 people · 2 mi SE
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 Newcastle's climate
What is the coldest month in Newcastle?
January, with a normal high of 30°F and a normal low of 15°F. The warmest is July (78°F by day, 60°F at night).
Does it snow in Newcastle?
Yes: 79 inches in a normal year, falling on 38 days with 0.1 inch or more, the most in February (20.3 inches).
What is the rainiest month in Newcastle?
October, with 4.97 in of precipitation in a normal year; the driest is August with 3.35 in.
What plant hardiness zone is Newcastle in?
The USDA's 2023 map puts Newcastle in zone 5b in ZIP code 04553, the nearest ZIP area. By the same method at Newcastle's NOAA station, the coldest night of a typical year reaches −9°F (30 years, 1991-2020): zone 6a.
How late can frost come in Newcastle?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 10. Waiting until May 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Maine climateThe statewide normals and every place in the state
- Wiscasset, ME11 miles from this station, 45.9°F a year
- Westport Island, ME14 miles from this station, 46.0°F a year
- Tenants Harbor, ME16 miles from this station, 46.4°F a year
- Gardiner, ME17 miles from this station, 45.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made