Climate and monthly weather forecast
Coos Bay, OR

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A unique sandy and rocky shore near a forest of pine trees in the Shore Acres State Park in Coos Bay, Oregon
A unique sandy and rocky shore near a forest of pine trees in the Shore Acres State Park in Coos Bay, Oregon

The climate of Coos Bay

Coos Bay is located in the state of Oregon, USA. It falls within the Mediterranean, warm summer zone of the Köppen Climate Classification, denoted as Csb. This classification implies a climate characterized by warm and dry summers, while winters are cool and mild. The city experiences a stable range of relative humidity throughout the year, fluctuating between 81% and 84%.

The temperature in Coos Bay displays a significant range from month to month. The coldest temperatures are noted in January, with a low of 41.7°F (5.4°C), and the highest temperatures can be expected in the warmer months of July and August, reaching a high of 66.9°F (19.4°C). Even during the peak of summer, Coos Bay maintains a relatively mild climate, a signature characteristic of the Mediterranean climate zone.

Precipitation patterns in Coos Bay showcase a significant variation over the course of the year. The city stays dry in summer, with July recording the least rainfall of only 0.16" (4mm), while December experiences the most rainfall, nearly 5.87" (149mm). The average number of rainy days per month also corresponds to this pattern, with only an average of 3.6 rainy days in July but increasing to an average of 18.6 rainy days in December.

In Coos Bay, snowfall is relatively rare and when it occurs, it does so in very minute quantities. Only minor traces of snow have been recorded in January and December.

The best time to visit Coos Bay

Taking into account the climate factors of Coos Bay, the best time to visit predominantly depends on the visitor's preference for weather conditions. However, considering the temperature, rainfall, and sunny days, the period from June to September appears most favorable for outdoor activities. During these months, the temperature fluctuates between 58.6°F (14.8°C) and 65.8°F (18.8°C), and rainfall is significantly less, varying from 0.16" (4mm) to 1.1" (28mm).

The worst time to visit Coos Bay

Since rainfall is quite abundant in winter months, from November to February, this period can be considered as the least favorable time to visit Coos Bay. December and January record the highest rainfall, 4.09" (104mm) and 5.87" (149mm) respectively, making it quite challenging for outdoor activities.

Spring weather in Coos Bay

Spring in Coos Bay, from March to May, sees a rise in temperature from 51.8°F (11°C) in March to 58.6°F (14.8°C) by May. The rainfall also tends to decrease during spring from 4.02" (102mm) in March to 1.69" (43mm) in May. During these months, cloudy skies start to clear, and sunshine hours increase from 6 hours in March to 8.8 hours in May.

Summer weather in Coos Bay

June marks the beginning of the summer season in Coos Bay. With temperatures staying between a comfortable 58.6°F (14.8°C) and 65.8°F (18.8°C), summer is characterized by long sunny days and scanty rainfall. From June to August, the city boasts an average of approximately 10 hours of sunshine per day and a substantial reduction in rainfall - from 1.69" (43mm) in June to a mere 0.16" (4mm) in July.

Autumn weather in Coos Bay

Autumn weather in Coos Bay, from September to November, presents a gradual decrease in temperature, dropping from 65.8°F (18.8°C) in September to 54.1°F (12.3°C) by November. This season shows an increase in rainfall and a shortening of daylight hours. In November, rainfall measures up to 4.09" (104mm), and daylight hours are reduced to 9.7 hours per day.

Winter weather in Coos Bay

Winter, from December to February, is characterized by cold temperatures, frequent rainfall, and fewer sunshine hours. December showcases the lowest average temperature of 41.7°F (5.4°C), highest average rainfall of 5.87" (149mm), and shortest daylight hours. Despite these less favorable conditions, snowfall remains remarkably rare in winter, with only minimal observations in the month of December.

Weather in January

The year commences with January weather, characterized by mild temperatures and a relatively high level of humidity over Coos Bay, Oregon. Compared to other months, the precipitation remains abundant with rainfall of 5.16" (131mm). Weather in January »

Weather in February

February's weather in Coos Bay, Oregon, reflects subtle differences when compared to January. The echoes of winter still resonate with a considerable amount of precipitation; however, rainfall decreases slightly to 4.84" (123mm). Weather in February »

Weather in March

The transition from late-winter to early-spring strikes Coos Bay in March. The precipitation, though still significant, further softens down to 4.02" (102mm). Despite this drop, the weather maintains considerable humidity while the wind exhibits a minor spike, a common occurrence in Oregon around this period. Weather in March »

Weather in April

April in Coos Bay sees a significant change in weather patterns, marking the spring season's full bloom. As temperatures steadily increase, the rainfall encounters a precipitous drop to 2.95" (75mm), allowing more dry days for outdoor adventures. Weather in April »

Weather in May

Moving into May, the beautiful city of Coos Bay, Oregon, witnesses the maturation of spring. As the temperatures rise, the rainfall sees an even steeper decrease to 1.69" (43mm), bringing dryness and warmth in the air. The wind speed continues to ease off, and the broader daylight hours resonate with the blithe spirit of spring. Weather in May »

Weather in June

June introduces summer to Coos Bay, and the weather takes on a decidedly warmer turn. As part of this transition, the rainfall plummets to a mere 0.75" (19mm), indicating one of the driest periods of the year. The wind holds steady, blowing at moderate speeds while the city experiences the longest daylight hours of the year. Weather in June »

Weather in July

In Coos Bay, July signifies the height of summer. This month surprises with the scarce rainfall of 0.16" (4mm), indicating the driest spell of the year. The wind, though consistent, does not relieve the rising mercury levels. With longer days and fewer clouds, the city basks in abundant sunshine. Weather in July »

Weather in August

The last summer month of August in Coos Bay sees mild changes in the weather. The rainfall takes a slight upward turn to 0.28" (7mm), yet the atmosphere remains predominantly dry. Slight changes in wind patterns accompany shifts in temperatures, hinting at autumn’s imminent arrival. Weather in August »

Weather in September

September brings Coos Bay into the comfortable clasp of autumn. Compared to the peak summer months, rainfall escalates a little to 1.1" (28mm), offering relief from the intense dryness. The wind carries whispers of the approaching change, gathering momentum. Weather in September »

Weather in October

October unveils the full impact of autumn on Coos Bay's weather. Heavy rainfall, up to 2.6" (66mm), becomes a more regular sight, cultivating a vibrant mix of hues in the city's foliage. Variable winds carry with them a cold sharpness, a reminder of the nearing winter. Weather in October »

Weather in November

Arriving in November, the late-autumn in Coos Bay promises considerably cooler weather. Standing out is the noticeable rise in precipitation with rainfall surging to 4.09" (104mm). The wind also acquires a pronounced chill, blowing more strongly with a reminder of the winter to come. Weather in November »

Weather in December

Finally, December rolls in, marking the advent of winter in Coos Bay. Seeing the highest rainfall of the year at 5.87" (149mm), the city is frequently under cloudy skies. Notably, the wind, bearing a cold snap, reaches its strongest speed in this month. Weather in December »
Updated: Aug 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How much does it rain?

Throughout the year, there are 153 rainfall days, and 33.5" (851mm) of precipitation is accumulated.

When does it snow?

January, February and November are months with snowfall.

How much does it snow?

Throughout the year, in Coos Bay, there are 0.7 snowfall days, and 0.31" (8mm) of snow is accumulated.

What is the month with the least sunshine in Coos Bay?

January and February, with an average of 4.4h of sunshine, are months with the least sunshine.

What are the most humid months?

February and August, with an average relative humidity of 84%, are most humid months.

When does it snow the most?

February is the month with the most snowfall. Snow falls for 0.3 days and accumulates 0.2" (5mm) of snow.

When is the lowest UV index?

The months with the lowest UV index are February and December, with an average maximum UV index of 2.

When it does not snow?

In Coos Bay, snow does not fall in March through October and December.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

What is the least humid month?

The months with the lowest humidity are April and October, with an average relative humidity of 81%.

When are the longest days?

June has the longest days of the year, with an average of 15h and 24min of daylight.

What is the driest month?

July is the month with the least rainfall. Rain falls for 3.6 days and accumulates 0.16" (4mm) of precipitation.

What month has the most sunshine?

With an average of 10.8h of sunshine, July has the most sunshine of the year.

What is the month with the highest UV index?

July is the month with the highest UV index, with an average maximum UV index of 5.

What is the warmest month?

August, with an average high of 66.9°F (19.4°C) and a low of 52.3°F (11.3°C), signifies the warmest month of the year in Coos Bay.

What time of the year is the coldest?

December is the coldest month, with the temperature often reaching an average high of 49.1°F (9.5°C) and an average low of 41.7°F (5.4°C).

What is the wettest month?

December is the month with the most rainfall in Coos Bay. Rain falls for 18.6 days and accumulates 5.87" (149mm) of precipitation.

What is the month with the shortest days?

With an average of 9h and 0min of daylight, December has the shortest days of the year.

Average temperature
Coos Bay, OR

Average temperature - Coos Bay, OR

The warmest month (with the highest average high temperature) is August (66.9°F).
The month with the lowest average high temperature is December (49.1°F).

The month with the highest average low temperature is August (52.3°F).
The coldest months (with the lowest average low temperature) are February and December (41.7°F).

Average pressure
Coos Bay, OR

Average pressure - Coos Bay, OR

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is September (30.01"Hg).

Average wind speed
Coos Bay, OR

Average wind speed - Coos Bay, OR

The windiest month (with the highest average wind speed) is March (9.1mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).

Average humidity
Coos Bay, OR

Average humidity - Coos Bay, OR

The months with the highest relative humidity are February and August (84%).
The months with the lowest relative humidity are April and October (81%).

Average rainfall
Coos Bay, OR

Average rainfall - Coos Bay, OR

The wettest month (with the highest rainfall) is December (5.87").
The driest month (with the least rainfall) is July (0.16").

Average rainfall days
Coos Bay, OR

Average rainfall days - Coos Bay, OR

The month with the highest number of rainy days is March (19.2 days).
The month with the least rainy days is August (3.5 days).

Average snowfall
Coos Bay, OR

Average snowfall - Coos Bay, OR

The month with the highest snowfall is February (0.2").
The months with the least snowfall are March, April, May, June, July, August, September, October and December (0").

Average snowfall days
Coos Bay, OR

Average snowfall days - Coos Bay, OR

The month with the highest number of snowfall days is February (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September and October (0 days).

Average daylight / Average sunshine
Coos Bay, OR

Average daylight / Average sunshine - Coos Bay, OR

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January and February (Average sunshine: 4h and 24min).

Average sunshine days
Coos Bay, OR

Average sunshine days - Coos Bay, OR

The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is February (9.7 days).

Average visibility
Coos Bay, OR

Average visibility - Coos Bay, OR

The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).

Coos Bay, Oregon, USA

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