St. Paul, Alaska climate: Normal weather by month, frost dates and records
St. Paul's normal year runs from 21°F March nights to 53°F August afternoons, with 24.3 inches of precipitation and 64 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 2.2°C, March lows of −6°C, August highs of 12°C, 618 mm of precipitation a year.
- NOAA stationSaint Paul Island Airport
- Station IDUSW00025713
- Location57.16°N 170.22°W
- Elevation35 ft (11 m)
- From the center4 miles
- Population439
On October 23, the normal high in St. Paul is 42°F and the normal low 34°F, and the chance of measurable rain or snow is 75%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for St. Paul.
- Jan 29° 21°
- Feb 29° 21°
- Mar 30° 21°
- Apr 34° 26°
- May 41° 32°
- Jun 48° 39°
- Jul 52° 44°
- Aug 53° 46°
- Sep 50° 42°
- Oct 44° 35°
- Nov 38° 30°
- Dec 33° 25°
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 St. Paul each month?
August is the warmest month, with normal highs of 53°F; March the coldest, with normal lows of 21°F. The most precipitation falls in October (3.32 in), the least in May (1.02 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 | 29°F | 21°F | 25.3°F | 1.61 | 16.5 | 17 | <1 | 27 | 7 h 20 min |
| February | 29°F | 21°F | 25.3°F | 1.43 | 11.1 | 16 | <1 | 25 | 9 h 30 min |
| March | 30°F | 21°F | 25.1°F | 1.29 | 9.6 | 14 | <1 | 29 | 11 h 40 min |
| April | 34°F | 26°F | 30.1°F | 1.04 | 5.3 | 12 | <1 | 25 | 14 h 10 min |
| May | 41°F | 32°F | 36.6°F | 1.02 | 0.8 | 12 | <1 | 15 | 16 h 30 min |
| June | 48°F | 39°F | 43.1°F | 1.31 | 0.0 | 11 | <1 | 2 | 17 h 50 min |
| July | 52°F | 44°F | 47.9°F | 1.98 | 0.0 | 14 | <1 | <1 | 17 h 20 min |
| August | 53°F | 46°F | 49.5°F | 3.06 | 0.0 | 18 | <1 | <1 | 15 h 20 min |
| September | 50°F | 42°F | 46.0°F | 3.00 | 0.0 | 20 | <1 | 2 | 12 h 50 min |
| October | 44°F | 35°F | 39.5°F | 3.32 | 1.6 | 23 | <1 | 9 | 10 h 30 min |
| November | 38°F | 30°F | 33.9°F | 2.97 | 7.1 | 23 | <1 | 18 | 8 h 10 min |
| December | 33°F | 25°F | 28.9°F | 2.30 | 12.3 | 22 | <1 | 24 | 6 h 40 min |
| Year (annual) | 40°F | 32°F | 35.9°F | 24.33 | 64.3 | 202 | <1 | 176 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −6°C | −3.7°C | 41 mm | 42 cm |
| February | −1°C | −6°C | −3.7°C | 36 mm | 28 cm |
| March | −1°C | −6°C | −3.8°C | 33 mm | 24 cm |
| April | 1°C | −3°C | −1.1°C | 26 mm | 13 cm |
| May | 5°C | 0°C | 2.6°C | 26 mm | 2 cm |
| June | 9°C | 4°C | 6.2°C | 33 mm | 0 cm |
| July | 11°C | 7°C | 8.8°C | 50 mm | 0 cm |
| August | 12°C | 8°C | 9.7°C | 78 mm | 0 cm |
| September | 10°C | 5°C | 7.8°C | 76 mm | 0 cm |
| October | 6°C | 2°C | 4.2°C | 84 mm | 4 cm |
| November | 3°C | −1°C | 1.1°C | 75 mm | 18 cm |
| December | 1°C | −4°C | −1.7°C | 58 mm | 31 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025713; 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 St. Paul?
No month's normal high reaches 65°F in St. Paul: the warmest is August at 53°F.
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 USW00025713.
When is the last frost in St. Paul?
In St. Paul, the last spring frost (32°F) comes after June 4 in half of years and after June 25 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 11 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
- June 41 year in 10 after June 25; 9 in 10 after May 16
- First autumn frost, half of years before
- September 281 year in 10 before September 11; 9 in 10 before October 15
NOAA puts the median frost-free season at 114 days, and the season without a hard freeze (28°F) at 149 days.
A hard freeze (28°F) comes after May 17 in half of springs and before October 15 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts St. Paul in zone 6b in ZIP code 99660. By the map's own method, the average of each year's coldest night over 1991-2020, St. Paul's NOAA station is in zone 6b: the coldest night of a typical year reaches −2°F (29 complete years).
Frost dates for every NOAA station in Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00025713; 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 St. Paul?
In a normal year in St. Paul, a 90°F day is rare, 176 nights fall to 32°F or colder and 202 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 176a normal year
- Days that stay below freezing
- 76high of 32°F or less
- Days with 0.01 inch of precipitation
- 202a normal year
- Days with 1 inch of snow or more
- 20a normal year
The highest temperature in this station's record (since 1892) is 66°F, on August 25, 1987; the lowest is −26°F, on January 27, 1919.
The wettest calendar year on that record is 1964, with 36.61 in; the snowiest season is 1963–64, with 139.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00025713; records: ACIS (NOAA Regional Climate Centers), station USW00025713. Records use complete months only; a month missing more than three days is left out.
How humid and windy is St. Paul, and how clear are its skies?
The summer (June-August) dew point averages 45°F. The muggiest month is July, with an average dew point of 47°F; the driest air comes in January (20°F). January is the windiest month (19.4 mph on average), and February has the most clear or nearly clear hours (16%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 20°F | 84% | 83% | 19.4 mph | – | – |
| February | 23°F | 85% | 83% | 17.7 mph | 16% | 58% |
| March | 22°F | 84% | 80% | 16.8 mph | – | – |
| April | 29°F | 86% | 81% | 14.4 mph | – | – |
| May | 37°F | 89% | 81% | 13.2 mph | – | – |
| June | 43°F | 92% | 86% | 11.8 mph | – | – |
| July | 47°F | 93% | 89% | 11.1 mph | – | – |
| August | 46°F | 91% | 86% | 13.3 mph | – | – |
| September | 39°F | 84% | 78% | 15.6 mph | – | – |
| October | 32°F | 82% | 79% | 16.9 mph | – | – |
| November | 27°F | 81% | 80% | 18.1 mph | – | – |
| December | 23°F | 82% | 81% | 18.0 mph | – | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00025713. 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 St. Paul?
Over a year 55% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around St. Paul, 2.3 kWh per square metre a day. March is the sunniest month (61%) and December the cloudiest (47%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 50% | 0.4 |
| February | 53% | 1.0 |
| March | 61% | 2.3 |
| April | 58% | 3.4 |
| May | 56% | 4.2 |
| June | 55% | 4.4 |
| July | 52% | 3.9 |
| August | 51% | 3.1 |
| September | 55% | 2.3 |
| October | 56% | 1.3 |
| November | 48% | 0.5 |
| December | 47% | 0.3 |
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 St. Paul need?
A normal year in St. Paul brings 10,585 heating degree days, 97% more than the median U.S. place (5,373), and 0 cooling degree days, 100% fewer than the median (908). Twelve months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 46 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,231 | 0 |
| February | 1,112 | 0 |
| March | 1,235 | 0 |
| April | 1,047 | 0 |
| May | 880 | 0 |
| June | 657 | 0 |
| July | 530 | 0 |
| August | 479 | 0 |
| September | 570 | 0 |
| October | 792 | 0 |
| November | 933 | 0 |
| December | 1,119 | 0 |
| Year (annual) | 10,585 | 0 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025713. 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 St. Paul been warmer than normal lately?
2024 averaged 36.5°F, 0.6°F above the 1991-2020 normal of 35.9°F. 3 of the 3 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2022 | 36.0°F | +0.1°F | 23.68 | – |
| 2023 | 36.7°F | +0.8°F | 28.49 | – |
| 2024 | 36.5°F | +0.6°F | 23.13 | – |
Over 111 complete years from 1840 to 2025, the station's annual mean temperature rose at a fitted 3.4°F per century (+0.19°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00025713; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does St. Paul's climate compare?
St. Paul is warmer than 46 of the other 84 places with their own NOAA record in Alaska, and wetter than 44. Across the 7,247 U.S. stations with normals, its annual mean of 35.9°F is warmer than 2%.
In the Köppen classification computed from these normals, St. Paul is ET: tundra. 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.
What do St. Paul's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near St. Paul. This page uses Saint Paul Island Airport; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| St. Paul (4 mi NE) USW00025711 | 4 mi E | 20 ft | 35.4°F | 21°F | 51°F | 24.9 | – | June 5 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about St. Paul's climate
What is the coldest month in St. Paul?
March, with a normal high of 30°F and a normal low of 21°F. The warmest is August (53°F by day, 46°F at night).
Does it snow in St. Paul?
Yes: 64 inches in a normal year, falling on 83 days with 0.1 inch or more, the most in January (16.5 inches).
What is the rainiest month in St. Paul?
October, with 3.32 in of precipitation in a normal year; the driest is May with 1.02 in.
What plant hardiness zone is St. Paul in?
The USDA's 2023 map puts St. Paul in zone 6b in ZIP code 99660. By the same method at St. Paul's NOAA station, the coldest night of a typical year reaches −2°F (29 years, 1991-2020): zone 6b.
How late can frost come in St. Paul?
In half of years the last 32°F night comes after June 4; in one year in ten it comes after June 25. Waiting until June 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- St. Paul in OctoberThis month day by day, its records and recent years
- Alaska climateThe statewide normals and every place in the state
- St. George, AK46 miles from this station, 36.7°F a year
- Dutch Harbor, AK267 miles from this station, 41.6°F a year
- Cold Bay, AK318 miles from this station, 39.3°F a year
- Bethel, AK390 miles from this station, 31.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made