A rainy Seattle August

If you thought it has been unusually wet this August in Seattle, you're right. In fact, so far, it is the 5th wettest August on record at Sea-tac airport. Here's a list of the rainiest August's on record:

1. 4.59" in 1975
2. 4.58" in 1968
3. 3.59" in 1977
4. 3.00" in 2004
5. 2.86" in 2008 (through August 26th)

The average precipitation is 1.07" in August. The top chart shows that there is about a 50% chance Seattle will get 0.75" of rain in any given August. So although August is pretty dry, rainy days in August are not all that unheard of in general.

The bottom chart shows that Seatac only gets over 2.5" of rain in August a little less frequently than once every ten years. Seattle gets over 3" of rain in August once every 20 years.