Weather on May 9

Boise, ID

55 Years of Data

Avg High
68°F
Avg Low
43°F
Warmest
2025
72°F avg
Coldest
2022
39°F avg

About This Date

May 9th in Boise, ID typically brings mild spring weather, with average highs around 68°F and lows near 43°F — a 25°F daily swing. Over 55 years of records, the warmest May 9th was in 2025 (72°F average), while the coldest was 2022 (39°F) — a 33°F range across recorded history. Precipitation has occurred on 24% of recorded May 9th dates, with snow falling 2% of the time. The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.

The last decade has been 3.4°F warmer on this date compared to 20-30 years ago.

Planning for May 9th in Boise, ID? Great weather for outdoor activities.

Warming Trend
0.4°F per decade on this date
YearHighLowAvgPrecipSnow
2025warmest88°57°72°
202475°38°56°
202362°42°52°0.48"
2022coldest44°33°39°0.66"0.5"
202163°36°49°
202081°48°64°
201968°49°58°
201879°56°67°
201774°44°59°
201661°46°53°
201576°45°60°
201463°45°54°0.69"
201384°52°68°
201282°49°65°
201162°39°51°
201067°41°54°
200967°38°52°
200863°42°52°
200785°54°69°
200660°34°47°
200560°45°52°1.14"
200469°45°57°
200355°45°50°0.03"
200263°43°53°
200170°47°58°
200062°49°55°0.36"
199952°29°40°
199862°47°54°
199784°46°65°
199666°35°51°
199572°44°58°0.03"
199486°48°67°
199369°37°53°
199265°41°53°
199156°37°46°
199071°33°52°
198983°53°68°0.08"
198867°44°55°
198787°52°69°
198665°39°52°0.1"
198569°39°54°
198466°51°59°
198349°37°43°
198256°37°46°0.08"
198172°38°55°
198055°44°50°0.28"
197961°39°50°
197878°48°63°0.38"
197766°40°53°0.2"
197680°48°64°
197573°50°62°
197465°50°57°
197367°44°55°
197263°33°48°
197172°47°59°
55 years of data from BOISE AIR TERMINAL

Browse Weather History

Weather data provided by NOAA Climate Data Online. Not for critical planning.