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April Weather in Issaquah, United States

Last updated: June 24, 2025

In Issaquah, United States during April, the average temperature hovers around 9°C (49°F). Temperatures can fluctuate significantly, with a minimum of -3°C (27°F) and a maximum reaching 28°C (82°F). Expect precipitation to average 144 mm (5.7 in) over approximately 15 days, and experience high humidity levels at around 84%.

April Temperature in Issaquah

In April in Issaquah, the average temperature is 9°C (49°F). The maximum can reach up to 28°C (82°F), while the minimum can drop as low as -3°C (27°F). Pack accordingly to enjoy a range of weather conditions during your travels.

April Weather in Issaquah: Daily Temperature Highs, Lows, and Averages

The chart illustrates April temperature patterns in Issaquah, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Issaquah, April typically has an average temperature of 9°C (49°F), with highs reaching up to 28°C (82°F) and lows dropping to around -3°C (27°F).
JanFebMarAprMayJunJulAugSepOctNovDec403844495560656560504540
Data source: Temperature data for Issaquah generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

April Precipitation in Issaquah

In Issaquah in April, the precipitation amount is 144 mm (5.7 in) during a span of 15 days.

April Precipitation Trends in Issaquah

The chart displays monthly precipitation patterns in Issaquah, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In Issaquah, April typically receives around 144 mm (5.7 inches) of precipitation spread over approximately 15 days.
JanFebMarAprMayJunJulAugSepOctNovDec20023415214485782823115205217235
Data source: Precipitation data for April generated using information from the Copernicus Climate Change Service.
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April Humidity in Issaquah

In Issaquah in April, humidity is 84%. With an average temperature of 9°C (49°F), this humidity feels like a chilly embrace, making travel uncomfortable as the dampness seeps into your clothes and lingers in the air, leaving you feeling cool yet clammy.

April Average Humidity in Issaquah

This chart illustrates the average monthly humidity levels in Issaquah, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in Issaquah is approximately 84%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%86%87%84%81%82%79%63%62%83%89%88%
Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in Issaquah

In Issaquah in April, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Issaquah, you can refer to this Hourly UV Index in Issaquah.

Maximum UV Index Levels in Issaquah for April

The chart shows the monthly maximum UV Index (UVI) for Issaquah in April, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In April, the maximum UV index in Issaquah typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689987522
Data source: Issaquah April UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How April Weather in Issaquah Compares to Other Months

Weather in Issaquah varies notably across the year, with each month offering distinct climate conditions. This page compares April’s weather to other months in Issaquah, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Issaquah, showing how April’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (40°F)199 mm (7.9 inches)86%low
February Weather4°C (39°F)234 mm (9.2 inches)86%moderate
March Weather7°C (44°F)152 mm (6.0 inches)87%moderate
April Weather9°C (49°F)144 mm (5.7 inches)84%high
May Weather13°C (55°F)85 mm (3.3 inches)81%very high
June Weather16°C (60°F)78 mm (3.1 inches)82%very high
July Weather18°C (65°F)28 mm (1.1 inches)79%very high
August Weather18°C (65°F)23 mm (0.9 inches)63%very high
September Weather15°C (60°F)115 mm (4.5 inches)62%high
October Weather10°C (50°F)204 mm (8.1 inches)83%moderate
November Weather7°C (45°F)217 mm (8.5 inches)89%low
December Weather4°C (40°F)235 mm (9.3 inches)88%low

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