Frost vs. freeze vs. hard freeze
The National Weather Service definitions at 36°F, 32°F and 28°F.
How to read frost date probabilities
What the 10%, 50% and 90% dates mean.
USDA hardiness zones explained
Zones, half zones and the 2023 map.
How cold is too cold to swim?
Cold shock thresholds and when to wear a wetsuit.
Satellite vs. buoy water temperatures
Why sources disagree and which we show.
UV index explained
Exposure categories and EPA sun protection advice.