Climate and monthly weather forecastPetersburg, AK
Climate and monthly weather forecast
The climate of Petersburg
Petersburg, Alaska, USA, experiences a Humid continental climate with no dry season and a warm summer, according to the Köppen climate classification. This Dfb climate predominant type denotes that this coastal town nestled in the southeastern part of Alaska, coordinates at an approximate latitude of 56.8°N and a longitude of 132.9°W.Throughout the year, Petersburg experiences substantial variations in temperature, precipitation, humidity, and daylight hours. Average high temperatures fluctuate from 32.4°F (0.2°C) to 59.7°F (15.4°C), whereas the average low temperatures range from 25.9°F (-3.4°C) to 50.2°F (10.1°C). The town's yearly humidity oscillates moderately with relative percentages in the low to mid-eighties.
Petersburg experiences more precipitation in comparison to the national average for the USA. The average rainfall varies between 2.01" (51mm) to 6.3" (160mm) throughout the year, with a noteworthy increase during the fall months. Snow is common during the colder months, with snowfall amounts ranging from 10.67" (271mm) in December to 13.46" (342mm) in March.
Maximum daylight hours can be as much as 17.7 hours in June, while December sees the least daylight with an average of around 6.9 hours. Alongside this, the town experiences decent sunshine throughout the year, with May offering the highest sunshine duration of 7.4 hours.
The best time to visit Petersburg
To take advantage of the most favorable weather conditions, summer emerges as the top choice to visit Petersburg. From June to August, the town sees the warmest temperatures with an average high from 55.4°F (13°C) to 59.7°F (15.4°C), and low temperatures oscillating from 46.2°F (7.9°C) to 50.2°F (10.1°C). Simultaneously, daylight hours extend up to approximately 16.5 to 17.7 hours, providing a lot of daylight for outdoor activities and exploration. The frequency of rainfall and snowfall also decreases, promoting dry and pleasant conditions for both inhabitants and visitors.The worst time to visit Petersburg
On the other hand, winter presents the least optimal period for visiting Petersburg. From December to February, the average high temperature drops to around 32.4°F (0.2°C) to 32.9°F (0.5°C) and the average low to 25.9°F (-3.4°C) to 27.3°F (-2.6°C). The daylight hours significantly reduce to 6.9 to 9.6 hours, limiting the visibility for outdoor activities. Furthermore, these months see an increase in snowfall, ranging from 10.67" (271mm) in December to 13.46" (342mm) in February.Spring weather in Petersburg
Spring in Petersburg transpires from March to May. During these months, the average high temperatures move up from 36.9°F (2.7°C) to 51.6°F (10.9°C), while the average low temperatures increase from 27.9°F (-2.3°C) to 41.9°F (5.5°C). Rainfall during this season varies from 3.54" (90mm) to 2.01" (51mm), and snowfall decrease continuously from 13.46" (342mm) in March to virtually no snowfall in May, marking the transition from winter to a milder climate.Summer weather in Petersburg
The onset of summer begins in June and lasts until August. This period marks the warmest months of the year, with average high temperatures ranging from 55.4°F (13°C) to 59.7°F (15.4°C). The average low temperatures too are mild, fluctuating from 46.2°F (7.9°C) to 50.2°F (10.1°C). Rainfall increases again, varying from 3.19" (81mm) to 5.55" (141mm), and there is no snowfall. The daylight hours are also at their peak, with approximately 17.1 to 17.7 hours of light each day.Autumn weather in Petersburg
From September to November, autumn season manifests in Petersburg. Average high temperatures begin to decrease, moving from 54.3°F (12.4°C) in September to 37°F (2.8°C) in November. During the same period, the average low temperatures drop from 46.4°F (8°C) to 32.4°F (0.2°C). Precipitation increases significantly during autumn months, reaching its peak at 6.3" (160mm) in October. Snowfall returns in November with an average of 6.38" (162mm), indicating the commencement of colder months.Winter weather in Petersburg
Winter in Petersburg begins in December and ends in February. During these months, average high temperatures drop to their lowest, ranging from 32.4°F (0.2°C) to 32.7°F (0.4°C). The average low temperatures plunge into the mid and high twenties. Precipitation decreases, with an average rainfall between 4.65" (118mm) to 6.02" (153mm). Snowfall rises to its highest; with February seeing the most snow of year at around 12.95" (329mm). The daylight hours are minimized to around 6.9 to 7.6 hours, marking the shortest days of the year.Weather in January
In Petersburg, Alaska, January is dominated by winter conditions. The snowy landscapes present a picturesque sight, and temperatures tend to dwell in the winter lows. With the highest snowfall of 11.73" (298mm) in the year, January flaunts its winter charm. Weather in January »Weather in February
Following January, February sustains the winter chill in Petersburg. The month presents marginally higher temperatures when compared to its predecessor. Snowfall is a consistent feature, complemented by a relatively low amount of rainfall. Weather in February »Weather in March
March experiences a break from the persistent cold, ushering in milder temperatures compared to the previous two months. Rainfall levels dip this month, with intermittent snowfall accompanying the mix. The length of daylight hours gradually increases, hinting at the approach of spring. Weather in March »Weather in April
April witnesses a significant transition in weather patterns in Petersburg. The blend of temperatures shifting towards warmth, coupled with the decreasing snowfall, points towards the advent of a unique spring season. Humidity levels and daylight hours rise, making outdoor activities more feasible. Weather in April »Weather in May
Perceived as the gateway to summer, May brings a perceptible change in Petersburg’s weather. Noticeable warming of temperatures further reduces the frequency of snowfall seen in the previous months. The number of daylight and sunshine hours significantly rise, highlighting the blooming of a delightful season. Weather in May »Weather in June
June marks the official start of summer, accompanied by ample daylight and sunshine hours in Petersburg. This period sees minimal snowfall, with heightened sea temperatures supporting marine life. Increased visibility and longer sunshine hours make outdoor activities more enticing. Weather in June »Weather in July
July, being the warmest month in the year, exhibits elevated temperatures and stricter UV indexes in Petersburg. As rainfall increases, humidity levels also rise, creating a unique balance of sun and rain. The high sea temperature of 52.1°F (11.2°C) makes it an appealing period for water-based activities. Weather in July »Weather in August
August witnesses a continuation of summer with increased rainfall punctuating the sunny days in Petersburg. Temperatures plateau in the warm range, marking it one of the hottest months. High sea temperatures and extended daylight hours call for outdoor activities and exploration. Weather in August »Weather in September
The change in seasons from summer to autumn becomes evident in September. Lower temperatures make a comeback, while rainfall is also partly prevalent, a telltale sign of the approaching winter. The days start to shorten, and cooler evenings usher in the mild autumnal charm. Weather in September »Weather in October
October sees a steady decline in temperature, locking Petersburg firmly in the embrace of fall. Accompanied by increased winds and rising humidity, the season of autumn truly sets in. Sea temperatures begin to fall, and daylight hours continue to decrease. Weather in October »Weather in November
November is a preface to the harsh winter that follows, characterized by plummeting temperatures and rising snowfall. The increased precipitation combined with reduced daylight hours makes for longer and colder nights. Low sea temperatures call for extra precautions in marine activities. Weather in November »Weather in December
Wrapping up the year, December introduces the unquestionable winter chills in Petersburg. Temperatures continue their descent, and the frequency of snowfall increases. Daylight hours hit a low point, and the city witnesses a unique Christmas atmosphere. Weather in December »Updated: Aug 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The months with the highest humidity are January and August, with an average relative humidity of 86%.
Throughout the year, there are 197.9 rainfall days, and 53.03" (1347mm) of precipitation is accumulated.
January through May, October through December are months with snowfall.
In Petersburg, during the entire year, snow falls for 47.5 days and aggregates up to 58.23" (1479mm) of snow.
January and November, with an average of 3.4h of sunshine, are months with the least sunshine.
The month with the most snowfall is March, when snow falls for 10.8 days and typically aggregates up to 13.46" (342mm) of snow.
The month with the coldest seawater is March, with an average ocean temperature of 41°F (5°C).
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from AKST to AKDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from AKDT to AKST.
With an average relative humidity of 81%, May is the least humid month.
May is the month with the least rainfall. Rain falls for 17.1 days and accumulates 2.01" (51mm) of precipitation.
May has the most sunshine of the year, with an average of 7.4h of sunshine.
June through September are months without snowfall.
June has the longest days of the year, with an average of 17h and 42min of daylight.
July, having an average high-temperature of 59.7°F (15.4°C) and an average low-temperature of 50.2°F (10.1°C), is the warmest month.
The months with the highest UV index are July and August, with an average maximum UV index of 4.
August is the month with the warmest seawater, with an average ocean temperature of 54.1°F (12.3°C).
The month with the most rainfall is October, when the rain falls for 20.1 days and typically aggregates up to 6.3" (160mm) of precipitation.
November and December, with an average maximum UV index of 1, are months with the lowest UV index.
Petersburg experiences its average lowest temperatures in December, reaching a peak of 32.4°F (0.2°C) and a minimum of 27.5°F (-2.5°C).
The month with the shortest days is December, with an average of 6h and 54min of daylight.
Average temperature
Petersburg, AK
The warmest month (with the highest average high temperature) is July (59.7°F).
The month with the lowest average high temperature is December (32.4°F).
The month with the highest average low temperature is July (50.2°F).
The coldest month (with the lowest average low temperature) is February (25.9°F).
Average pressure
Petersburg, AK
- Average pressure in January:
29.85"Hg - Average pressure in February:
29.95"Hg - Average pressure in March:
29.85"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
30"Hg - Average pressure in June:
29.98"Hg
- Average pressure in July:
30.05"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
29.91"Hg - Average pressure in October:
29.87"Hg - Average pressure in November:
29.8"Hg - Average pressure in December:
29.88"Hg
The month with the highest atmospheric pressure is July (30.05"Hg).
The month with the lowest atmospheric pressure is November (29.8"Hg).
Average wind speed
Petersburg, AK
- Average wind speed in January:
8.2mph - Average wind speed in February:
7.2mph - Average wind speed in March:
6.7mph - Average wind speed in April:
5.7mph - Average wind speed in May:
4.6mph - Average wind speed in June:
4.1mph
- Average wind speed in July:
3.9mph - Average wind speed in August:
4.3mph - Average wind speed in September:
5.7mph - Average wind speed in October:
6.7mph - Average wind speed in November:
7.7mph - Average wind speed in December:
7.7mph
The windiest month (with the highest average wind speed) is January (8.2mph).
The calmest month (with the lowest average wind speed) is July (3.9mph).
Average humidity
Petersburg, AK
The months with the highest relative humidity are January and August (86%).
The month with the lowest relative humidity is May (81%).
Average rainfall
Petersburg, AK
- Average rainfall in January:
6.02" - Average rainfall in February:
3.74" - Average rainfall in March:
3.58" - Average rainfall in April:
3.54" - Average rainfall in May:
2.01" - Average rainfall in June:
3.19"
The wettest month (with the highest rainfall) is October (6.3").
The driest month (with the least rainfall) is May (2.01").
Average rainfall days
Petersburg, AK
- Average rainfall days in January:
15.8 days - Average rainfall days in February:
9.5 days - Average rainfall days in March:
12.9 days - Average rainfall days in April:
18.1 days - Average rainfall days in May:
17.1 days - Average rainfall days in June:
19.3 days
- Average rainfall days in July:
17 days - Average rainfall days in August:
17.7 days - Average rainfall days in September:
17.5 days - Average rainfall days in October:
20.1 days - Average rainfall days in November:
18.3 days - Average rainfall days in December:
14.6 days
The month with the highest number of rainy days is October (20.1 days).
The month with the least rainy days is February (9.5 days).
Average snowfall
Petersburg, AK
- Average snowfall in January:
11.73" - Average snowfall in February:
12.95" - Average snowfall in March:
13.46" - Average snowfall in April:
2.6" - Average snowfall in May:
0.12" - Average snowfall in June:
0"
The month with the highest snowfall is March (13.46").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Petersburg, AK
- Average snowfall days in January:
8.6 days - Average snowfall days in February:
9.1 days - Average snowfall days in March:
10.8 days - Average snowfall days in April:
3.8 days - Average snowfall days in May:
0.2 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.2 days - Average snowfall days in November:
6.4 days - Average snowfall days in December:
8.4 days
The month with the highest number of snowfall days is March (10.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature
Petersburg, AK
The best month for swimming (with the highest average sea temperature) is August (54.2°F).
The coldest month (with the lowest average sea temperature) is March (41°F).
Average daylight / Average sunshine
Petersburg, AK
- Average daylight in January:
7h and 36min - Average daylight in February:
9h and 36min - Average daylight in March:
11h and 54min - Average daylight in April:
14h and 18min - Average daylight in May:
16h and 30min - Average daylight in June:
17h and 42min
- Average daylight in July:
17h and 6min - Average daylight in August:
15h and 6min - Average daylight in September:
12h and 42min - Average daylight in October:
10h and 18min - Average daylight in November:
8h and 6min - Average daylight in December:
6h and 54min
The month with the longest days is June (Average daylight: 17h and 42min).
The month with the shortest days is December (Average daylight: 6h and 54min).
- Average sunshine in January:
3h and 24min - Average sunshine in February:
4h and 12min - Average sunshine in March:
5h and 12min - Average sunshine in April:
6h and 42min - Average sunshine in May:
7h and 24min - Average sunshine in June:
7h and 6min
- Average sunshine in July:
6h and 48min - Average sunshine in August:
6h and 54min - Average sunshine in September:
6h and 42min - Average sunshine in October:
4h and 12min - Average sunshine in November:
3h and 24min - Average sunshine in December:
3h and 48min
The month with the most sunshine is May (Average sunshine: 7h and 24min).
The months with the least sunshine are January and November (Average sunshine: 3h and 24min).
Average sunshine days
Petersburg, AK
- Average sunshine days in January:
10.5 days - Average sunshine days in February:
12.3 days - Average sunshine days in March:
11.7 days - Average sunshine days in April:
9.1 days - Average sunshine days in May:
11.3 days - Average sunshine days in June:
9 days
- Average sunshine days in July:
11.8 days - Average sunshine days in August:
12.3 days - Average sunshine days in September:
11.5 days - Average sunshine days in October:
10.1 days - Average sunshine days in November:
8 days - Average sunshine days in December:
12.5 days
The month with the most sunshine days is December (12.5 days).
The month with the least sunshine days is November (8 days).
Average UV index
Petersburg, AK
The months with the highest UV index are July and August (UV index 4).
The months with the lowest UV index are November and December (UV index 1).
Average cloud cover
Petersburg, AK
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are February and May (Cloud cover 54).
Average visibility
Petersburg, AK
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
