August weather forecast
North Cascades National Park, WA

August emulates July with the temperature also reaching a maximum average of 70°F (21.1°C). The park’s weather, however, remains predictably sunny and warm, providing excellent conditions for exploring and enjoying its majestic landscape. As a testament to its alluring appeal, August often sees the highest number of visitors taking advantage of the weather and long daylight hours. Despite less rainfall and only nine rainy days, the park maintains its lush green appearance. A slightly increased amount of sunshine hours compared to previous months captures the epitome of summer in the park.

Temperature

In North Cascades National Park, the months of July and August register the highest average temperatures, peaking at 69.8°F (21°C).

Rainfall

August is the month with the least rainfall. Rain falls for 9 days and accumulates 1.65" (42mm) of precipitation.

Daylight

The average length of the day in August is 14h and 18min.
On the first day of the month, sunrise is at 5:40 am and sunset at 8:42 pm. On the last day of August, sunrise is at 6:21 am and sunset at 7:48 pm PDT.

Sunshine

In North Cascades National Park, the average sunshine in August is 8h.

UV index

The months with the highest UV index are June through August, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum UV index of 7 during August leads to these instructions:
Exercise precautions and adapt sun safety practices. Defence against skin and eye affliction is paramount. Stay out of direct sunlight and seek shade between 10 a.m. and 4 p.m., when UV radiation is strongest, but remember that shade devices may not offer full sun protection. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.