Ketchikan, Alaska climate: Normal weather by month, frost dates and records
Ketchikan's normal year runs from 32°F January nights to 65°F August afternoons, with 149.5 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.8°C, January lows of 0°C, August highs of 18°C, 3,798 mm of precipitation a year.
- NOAA stationKetchikan International Airport
- Station IDUSW00025325
- Location55.36°N 131.71°W
- Elevation76 ft (23 m)
- Population8,033
On October 23, the normal high in Ketchikan is 49°F and the normal low 40°F, and the chance of measurable rain or snow is 76%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ketchikan.
- Jan 40° 32°
- Feb 41° 32°
- Mar 44° 32°
- Apr 50° 37°
- May 57° 43°
- Jun 61° 49°
- Jul 65° 53°
- Aug 65° 53°
- Sep 59° 48°
- Oct 51° 41°
- Nov 44° 36°
- Dec 40° 33°
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 Ketchikan each month?
August is the warmest month, with normal highs of 65°F; January the coldest, with normal lows of 32°F. The most precipitation falls in October (18.37 in), the least in June (7.02 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. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 32°F | 35.6°F | 16.17 | 22 | <1 | 15 | 7 h 40 min |
| February | 41°F | 32°F | 36.2°F | 11.80 | 17 | <1 | 16 | 9 h 40 min |
| March | 44°F | 32°F | 38.0°F | 10.98 | 21 | <1 | 16 | 11 h 40 min |
| April | 50°F | 37°F | 43.5°F | 10.25 | 19 | <1 | 7 | 14 h |
| May | 57°F | 43°F | 50.1°F | 8.68 | 16 | <1 | 1 | 16 h 10 min |
| June | 61°F | 49°F | 55.3°F | 7.02 | 16 | <1 | <1 | 17 h 20 min |
| July | 65°F | 53°F | 58.8°F | 7.33 | 16 | <1 | <1 | 17 h |
| August | 65°F | 53°F | 59.0°F | 11.30 | 17 | <1 | <1 | 15 h 10 min |
| September | 59°F | 48°F | 53.6°F | 14.30 | 20 | <1 | <1 | 12 h 50 min |
| October | 51°F | 41°F | 46.2°F | 18.37 | 23 | <1 | 3 | 10 h 40 min |
| November | 44°F | 36°F | 39.7°F | 17.07 | 24 | <1 | 9 | 8 h 30 min |
| December | 40°F | 33°F | 36.4°F | 16.27 | 22 | <1 | 14 | 7 h 10 min |
| Year (annual) | 51°F | 41°F | 46.0°F | 149.54 | 233 | <1 | 82 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | 0°C | 2.0°C | 411 mm |
| February | 5°C | 0°C | 2.3°C | 300 mm |
| March | 6°C | 0°C | 3.3°C | 279 mm |
| April | 10°C | 3°C | 6.4°C | 260 mm |
| May | 14°C | 6°C | 10.1°C | 220 mm |
| June | 16°C | 10°C | 12.9°C | 178 mm |
| July | 18°C | 12°C | 14.9°C | 186 mm |
| August | 18°C | 12°C | 15.0°C | 287 mm |
| September | 15°C | 9°C | 12.0°C | 363 mm |
| October | 11°C | 5°C | 7.9°C | 467 mm |
| November | 7°C | 2°C | 4.3°C | 434 mm |
| December | 5°C | 0°C | 2.4°C | 413 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Annette Island Airport (23 miles away), gets 35 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025325; 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 Ketchikan?
No month's normal high reaches 65°F in Ketchikan: the warmest is August at 65°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 USW00025325.
When is the last frost in Ketchikan?
In Ketchikan, the last spring frost (32°F) comes after April 22 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 23 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 221 year in 10 after May 9; 9 in 10 after April 2
- First autumn frost, half of years before
- October 231 year in 10 before October 3; 9 in 10 before November 10
NOAA puts the median frost-free season at 185 days, and the season without a hard freeze (28°F) at 225 days.
A hard freeze (28°F) comes after March 31 in half of springs and before November 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ketchikan in zone 8a in ZIP code 99926, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Ketchikan's NOAA station is in zone 7b: the coldest night of a typical year reaches 7°F (28 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 Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00025325; 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 Ketchikan?
In a normal year in Ketchikan, a 90°F day is rare, 82 nights fall to 32°F or colder and 233 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
- 82a normal year
- Days that stay below freezing
- 12high of 32°F or less
- Days with 0.01 inch of precipitation
- 233a normal year
The highest temperature in this station's record (since 1910) is 96°F, on June 25, 1913; the lowest is −7°F, on January 23, 1916.
The wettest calendar year on that record is 2005, with 196.03 in; the snowiest season is 1975–76, with 82.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00025325; records: ACIS (NOAA Regional Climate Centers), station USW00025325. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Ketchikan, and how clear are its skies?
The summer (June-August) dew point averages 52°F. The muggiest month is July, with an average dew point of 53°F; the driest air comes in February (29°F). April is the windiest month (8.9 mph on average), and July has the most clear or nearly clear hours (36%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 32°F | 83% | 79% | 8.8 mph | 24% | 62% |
| February | 29°F | 76% | 67% | 8.1 mph | 34% | 53% |
| March | 34°F | 79% | 67% | 8.4 mph | 27% | 56% |
| April | 39°F | 76% | 62% | 8.9 mph | 33% | 46% |
| May | 46°F | 77% | 65% | 8.3 mph | 33% | 48% |
| June | 50°F | 80% | 69% | 8.1 mph | 28% | 48% |
| July | 53°F | 80% | 68% | 7.9 mph | 36% | 42% |
| August | 52°F | 86% | 75% | 7.4 mph | – | – |
| September | 46°F | 87% | 78% | 7.8 mph | 29% | 55% |
| October | 38°F | 85% | 80% | 8.2 mph | – | – |
| November | 33°F | 85% | 83% | 8.2 mph | – | – |
| December | 31°F | 84% | 82% | 8.4 mph | 31% | 61% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00025325. 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 Ketchikan?
Over a year 55% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Ketchikan, 2.4 kWh per square metre a day. May is the sunniest month (59%) and November the cloudiest (44%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 45% | 0.5 |
| February | 56% | 1.3 |
| March | 54% | 2.2 |
| April | 58% | 3.6 |
| May | 59% | 4.5 |
| June | 55% | 4.6 |
| July | 54% | 4.2 |
| August | 57% | 3.6 |
| September | 54% | 2.4 |
| October | 50% | 1.3 |
| November | 44% | 0.6 |
| December | 45% | 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 Ketchikan need?
A normal year in Ketchikan brings 6,917 heating degree days, 29% more than the median U.S. place (5,373), and 16 cooling degree days, 98% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 921 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 911 | 0 |
| February | 806 | 0 |
| March | 837 | 0 |
| April | 645 | 0 |
| May | 462 | 0 |
| June | 294 | 3 |
| July | 198 | 7 |
| August | 192 | 6 |
| September | 342 | 0 |
| October | 583 | 0 |
| November | 761 | 0 |
| December | 887 | 0 |
| Year (annual) | 6,917 | 16 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025325. 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 Ketchikan been warmer than normal lately?
2024 averaged 46.8°F, 0.8°F above the 1991-2020 normal of 46.0°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 45.0°F | −1.0°F | 143.73 |
| 2022 | 46.2°F | +0.2°F | 154.38 |
| 2023 | 47.8°F | +1.8°F | 175.54 |
| 2024 | 46.8°F | +0.8°F | 132.90 |
Over 83 complete years from 1914 to 2025, the station's annual mean temperature rose at a fitted 1.0°F per century (+0.05°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00025325; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Ketchikan's climate compare?
Ketchikan is warmer than 84 of the other 84 places with their own NOAA record in Alaska, and wetter than 70. Across the 7,247 U.S. stations with normals, its annual mean of 46.0°F is warmer than 23%.
In the Köppen classification computed from these normals, Ketchikan is Cfb: temperate, 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 Ketchikan 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.
- Saxman, AK377 people · 5 mi SE
- Loring, AK0 people · 18 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Ketchikan's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Ketchikan. This page uses Ketchikan International Airport; the others differ by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Beaver Falls USC00500657 | 1 mi E | 35 ft | 47.3°F | 32°F | 66°F | 157.3 | – | April 4 |
| Ketchikan (10 mi N) USC00504594 | 8 mi NW | 295 ft | 45.6°F | 31°F | 65°F | 104.7 | – | April 20 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Ketchikan's climate
What is the coldest month in Ketchikan?
January, with a normal high of 40°F and a normal low of 32°F. The warmest is August (65°F by day, 53°F at night).
Does it snow in Ketchikan?
Yes. NOAA publishes no 1991-2020 snowfall normal for Ketchikan's NOAA station; the nearest record that keeps one, Annette Island Airport (23 miles away), records 35 inches of snow in a normal year.
What is the rainiest month in Ketchikan?
October, with 18.37 in of precipitation in a normal year; the driest is June with 7.02 in.
What plant hardiness zone is Ketchikan in?
The USDA's 2023 map puts Ketchikan in zone 8a in ZIP code 99926, the nearest ZIP area. By the same method at Ketchikan's NOAA station, the coldest night of a typical year reaches 7°F (28 years, 1991-2020): zone 7b.
How late can frost come in Ketchikan?
In half of years the last 32°F night comes after April 22; in one year in ten it comes after May 9. Waiting until May 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ketchikan in OctoberThis month day by day, its records and recent years
- Alaska climateThe statewide normals and every place in the state
- Metlakatla, AK22 miles from this station, 45.7°F a year
- Annette Island Airport, AK22 miles from this station, 47.7°F a year
- Thorne Bay, AK39 miles from this station, 44.2°F a year
- Klawock, AK55 miles from this station, 45.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made