August weather forecast
Petersburg, AK

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Colorful buildings, docked ships in Quaint fishing village in Petersburg, Alaska, on Mitkof Island
Colorful buildings, docked ships in Quaint fishing village in Petersburg, Alaska, on Mitkof Island

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. However, by the end of August, the city starts preparing for the onset of autumn. With August, the last vestiges of summer can be noted, and a swift shift towards cooler weather is on the horizon.

Temperature

Petersburg observes a minor difference in average high-temperatures between July's 59.7°F (15.4°C) and August's 59°F (15°C). Throughout August, Petersburg records a steady low-temperature average of 50°F (10°C), a minor decrease from its daytime counterpart.

Humidity

The months with the highest humidity are January and August, with an average relative humidity of 86%.

Rainfall

In Petersburg, in August, during 17.7 rainfall days, 5.55" (141mm) of precipitation is typically accumulated. Throughout the year, there are 197.9 rainfall days, and 53.03" (1347mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Ocean temperature

August is the month with the warmest seawater, with an average ocean temperature of 54.1°F (12.3°C).
Note: With the appropriate swimsuit, one can swim in 54.1°F (12.3°C) even if temperatures dip below 50°F (10°C); otherwise, be ready for cold shock and breath issues. A fleeting swim around 55.4°F (13°C) is distressing.

Daylight

In August, the average length of the day is 15h and 5min.
On the first day of the month, sunrise is at 4:53 am and sunset at 9:02 pm. On the last day of August, sunrise is at 5:54 am and sunset at 7:49 pm AKDT.

Sunshine

In August, the average sunshine is 6.9h.

UV index

The months with the highest UV index are July and August, with an average maximum UV index of 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: An average maximum UV index of 4 in August leads to these recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Updated: Aug 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Petersburg in August?

In Petersburg, 59°F (15°C) is the average high-temperature and 50°F (10°C) is the average low-temperature during August.

What are the most humid months?

January and August, with an average relative humidity of 86%, are most humid months.

What is the average humidity in August?

In August, the average relative humidity is 86%.

How many days does it rain in August?

In Petersburg, in August, it is raining for 17.7 days, with typically 5.55" (141mm) of accumulated precipitation.

When it does not snow?

June through September are months without snowfall.

When is the ocean warmest?

August is the month with the warmest seawater, with an average ocean temperature of 54.1°F (12.3°C).

How cold is the water in August?

In August, the average ocean temperature is 54.1°F (12.3°C). Swimming in 54.1°F (12.3°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

How many hours of daylight does Petersburg have in August?

In Petersburg, the average day length in August is 15h and 5min.

When are sunrise and sunset in August?

On the first day of August in Petersburg, sunrise is at 4:53 am and sunset at 9:02 pm. On the last day of the month, sunrise is at 5:54 am and sunset at 7:49 pm AKDT.

How many hours of sunshine does Petersburg have in August?

The average sunshine duration in August is 6.9h.

What are the months with the highest UV index?

The months with the highest UV index are July and August, with an average maximum UV index of 4.

What is the UV index intensity in August?

In Petersburg, the average daily maximum UV index in August is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Petersburg, AK

Average temperature in August - Petersburg, AK
  • Average high temperature in August: 59°F

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).

  • Average low temperature in August: 50°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 in August
Petersburg, AK

Average pressure in August - Petersburg, AK
  • Average pressure in August: 29.98"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 in August
Petersburg, AK

Average wind speed in August - Petersburg, AK
  • Average wind speed in August: 4.3mph

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 in August
Petersburg, AK

Average humidity in August - Petersburg, AK
  • Average humidity in August: 86%

The months with the highest relative humidity are January and August (86%).
The month with the lowest relative humidity is May (81%).

Average rainfall in August
Petersburg, AK

Average rainfall in August - Petersburg, AK
  • Average rainfall in August: 5.55"

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 in August
Petersburg, AK

Average rainfall days in August - Petersburg, AK
  • Average rainfall days in August: 17.7 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 in August
Petersburg, AK

Average snowfall in August - Petersburg, AK
  • Average snowfall in August: 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 in August
Petersburg, AK

Average snowfall days in August - Petersburg, AK
  • Average snowfall days in August: 0 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 in August
Petersburg, AK

Average sea temperature in August - Petersburg, AK
  • Average sea temperature in August: 54.2°F

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 in August /
Average sunshine in August
Petersburg, AK

Average daylight in August / Average sunshine in August - Petersburg, AK
  • Average daylight in August: 15h and 1min

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 August: 6h and 5min

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 in August
Petersburg, AK

Average sunshine days in August - Petersburg, AK
  • Average sunshine days in August: 12.3 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 in August
Petersburg, AK

Average UV index in August - Petersburg, AK
  • Average UV index in August: 4

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 in August
Petersburg, AK

Average cloud cover in August - Petersburg, AK
  • Average cloud cover in August: 57

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 in August
Petersburg, AK

Average visibility in August - Petersburg, AK
  • Average visibility in August: 5mi

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).

Petersburg, Alaska, USA

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