Moving from Seattle to Phoenix
A climate comparison of two homes: Washington to Arizona. The dates below come from the nearest official weather station to each place.
Climate Match
Your growing season runs 107 days longer, 247 days becomes 354 days.
Seattle, WA to Phoenix, AZ
The full comparison
| Measure | From | To | Change |
|---|---|---|---|
| Frost-free season | 247 days | 354 days | 107 days longer |
| Last spring frost | March 13 | January 8 | 64 days earlier |
| Warmest month | 20C in August | 34C in July | 14C hotter |
| Coldest month | 6C in December | 12C in December | 6C warmer |
Moving from Seattle to Phoenix reshapes the home year. Winters get 6C warmer. Summers get 14C hotter. Your growing season is 107 days longer. Plan on a new rhythm for the house and garden.
What changes about the house
- Cooling: hotter peaks make air conditioning or shading more important. Check attic insulation and window sealing so the house does not trap heat.
- Garden: a longer frost-free season opens more crop choices and succession sowings. Raised beds warm earlier in spring.
Season by season
Spring starts earlier
Your last spring frost moves from March 13 to January 8, 64 days earlier. Start planting and outdoor prep sooner.
Summers run hotter
The warmest month goes from 20C in August to 34C in July. Air conditioning, shading, and cooling-load planning matter more.
Winters turn milder
Winter coldest month goes from 6C in December to 12C in December. Heating loads drop, but frozen-pipe and ice-storm prep may still apply.
Tools for both places
Moving from Seattle to Phoenix, answered
What is the biggest climate change from Seattle to Phoenix?
Your growing season runs 107 days longer, 247 days becomes 354 days. That is the largest shift in the 30-year climate record.
How are these numbers computed?
From official 30-year climate normals at the nearest station to each place: Seattle Boeing Fld near Seattle and Phoenix Deer Valley Muni Ap near Phoenix. They are planning averages, not forecasts; local microclimates can run a week or two off the station record.
Does the comparison work in reverse?
Yes. Open the comparison tool and swap the two places; the deltas reverse direction but the match score stays the same.
Method and sources
Temperatures and frost dates are from the 30-year climate normals at Seattle Boeing Fld (near Seattle, WA) and Phoenix Deer Valley Muni Ap (near Phoenix, AZ). Canadian data is from Environment and Climate Change Canada; United States data is from NOAA NCEI. These are planning averages, not forecasts. See the methodology page for the full calculation.