What’s a good source for historical temperature data?
![](https://secure.gravatar.com/avatar/7627b5a8ac1c9627d4676697e1e0e937?s=52&d=https%3A%2F%2Fimages.greenbuildingadvisor.com%2Fapp%2Favatars%2F200x200%2Fd.png&r=g)
What’s a good place to get historical temperature data for a relatively long period, say 10 years or more? This is for the Seattle, WA area. Ideally this would be impeccable data that no one would argue with.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb1.png)
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb2.png)
Replies
David,
Here's an online site that gives the historical average temperature in Seattle for every day of the year:
http://www.accuweather.com/en/us/seattle-wa/98104/march-weather/351409?monyr=3/1/2015
Gentlemen, thanks.
There's a guy here using data from his personal weather station, showing that average temps are decreasing since about 2000. There are counterclaims being made as well. I'd like to see authoritative HDD data for that period or similar. Longer would be better.
weatherspark.com has temperature, dew-point, and precipitation data going back decades for many locations, rendered in a graphical format, with pull down menus to select what/how you want it displayed.
http://weatherspark.com/#!dashboard;a=USA/WA/Seattle
If you want to know what the temperature was at 5AM on October 6th 1994, you can scroll & zoom in to take a peek at what the exact conditions were. (It was 53F, with a dew point 51F, and 90% cloud cover, but not raining, with effectively dead-calm winds in Seattle at that time & date.)