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Normal weather for West Lake Sammamish in September

It's pleasantly warm in September in West Lake Sammamish with an average temperature of 22°C. Temperatures this month range from a low of 19°C to a high of 25°C. At night, you can expect temperatures between 12°C and 16°C.

In September, there is an average of 52 mm of precipitation, spread over 8 days. The wind speed is around 3 Bft, mostly coming from the Southwest.

West Lake Sammamish in September

New York
Temperature Average Temperature
22°C 27°C
Sun High Temp
25°C 31°C
Sun Low Temp
19°C 21°C
Rain Total Precipitation
52 mm 57 mm
Rain Rainy Days
8 days 9 days

Start of September

The month of September starts in West Lake Sammamish with warm temps, averaging around 25°C during the day and nights around 15°C. There’s little chance of precipitation. The weather’s mostly sunny and dry.

With the temperature difference between day and night, it’s smart to wear layers. A T-shirt, light pants or skirt, and a light jacket are great for the day. For the evening and morning, a shirt, maybe a light sweater, and thin pants are recommended.

Mid September

By mid-September, daytime temps drop to around 22°C, with nights around 14°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.

Since it cools down at night, it’s a good idea to wear layers. A T-shirt, light pants or skirt, and a light jacket are great for the day. In the evening and morning, choose a light jacket, sweater or hoodie, and long pants.

End of September

By the end of September, the average daytime temperature in West Lake Sammamish is around 21°C, while nighttime temps are about 13°C. A shower might pop up, but overall, the weather will be dry and sunny.

Because temperatures drop in the evening, wearing layers is recommended. During the day, a shirt, maybe a light sweater, and thin pants will do. In the evening and morning, choose a light jacket, sweater or hoodie, and long pants.

UV index

The UV index is a maximum of 6 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.

Is September a good time to visit West Lake Sammamish?

Looking for great weather? September is a good time to be in West Lake Sammamish. The temperatures are nice, and there’s not too much rain.

Temperature records for West Lake Sammamish in September

Check out the climate of West Lake Sammamish for all months and discover the best travel time

Daily Temperature in September in West Lake Sammamish

This chart shows the average daily high and low temperatures in September for West Lake Sammamish, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.

Daily Temperature in September in West Lake Sammamish

Daily Precipitation in September in West Lake Sammamish

The chart below shows the average daily precipitation in September for West Lake Sammamish, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.

A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for September, you can expect about 8 days of precipitation in West Lake Sammamish.

Daily Precipitation in September in West Lake Sammamish

Daily UV Index in September in West Lake Sammamish

This chart shows the average daily UV index in September in West Lake Sammamish, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.

Daily UV Index in September in West Lake Sammamish

Temperature in September in West Lake Sammamish Over the Years

This chart shows the average temperature in September in West Lake Sammamish, measured in degrees Celsius, over the past few years.

Temperature in September in West Lake Sammamish Over the Years

Total Precipitation in September in West Lake Sammamish Over the Years

This chart shows the average precipitation in September in West Lake Sammamish, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.

Precipitation in September in West Lake Sammamish Over the Years

Daily Climate in September for West Lake Sammamish

Click on any day in September to get detailed info about the usual weather on that day in West Lake Sammamish. Check out the historical temperatures and precipitation over the past 10 years on this day.

Weather experiences in September in West Lake Sammamish

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Average Weather in West Lake Sammamish by Month

Click on a month below to see detailed weather info for West Lake Sammamish. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.


Or check out the climate of West Lake Sammamish for all months at once

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