Frost Dates: First and last frost dates for Mud Mtn Dam, WA
ℹ️ How to read these charts for the spring
As spring unfolds, the risk of frost gradually decreases each day until your tender plants are finally safe. The probabilities shown in the chart help you make smart decisions about when to plant.
While frost typically forms at 32°F, tender plants can be damaged even when temperatures are slightly higher. Air temperatures are often measured several feet above the ground, but temperatures at plant level can be several degrees colder. Protected areas like porches help by blocking radiational cooling. Given these variables, we consider 36°F the "caution zone" for frost-sensitive plants.
Key dates for your spring planting:
- By June 7, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
- Around May 18, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
- Before May 5, there's still an 80% risk of frost — too early for tomatoes and other tender plants unless you're prepared to protect them
If the 10-day forecast shows no temperatures below 40°F, you might safely plant earlier than the above dates suggest. Many gardeners watch for this weather window to get a head start on the growing season.
| Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| Last 16° | Feb 16 | Feb 2 | Jan 22 | Jan 11 | Dec 28 | -- | -- | -- | -- |
| Last 20° | Mar 2 | Feb 20 | Feb 12 | Feb 5 | Jan 29 | Jan 23 | Jan 15 | Jan 6 | Dec 19 |
| Last 24° | Mar 19 | Mar 5 | Feb 23 | Feb 15 | Feb 7 | Jan 30 | Jan 21 | Jan 11 | Dec 28 |
| Last 28° | Apr 18 | Apr 9 | Apr 2 | Mar 27 | Mar 21 | Mar 15 | Mar 9 | Mar 2 | Feb 21 |
| Last 32° | May 13 | May 7 | May 2 | Apr 28 | Apr 24 | Apr 20 | Apr 16 | Apr 11 | Apr 4 |
| Last 36° | Jun 7 | May 31 | May 26 | May 22 | May 18 | May 14 | May 10 | May 5 | Apr 28 |
ℹ️ How to read these charts for the fall
As summer ends in Mud Mtn Dam, WA, nighttime temperatures begin to drop, and your risk of frost increases with each passing day. Knowing when to expect frost helps you harvest sensitive crops and extend your growing season with protection methods.
The chart below shows the probability of experiencing specific temperatures on various dates. Here's what this means for your garden:
These probabilities help you time your end-of-season harvests and know when to apply protective measures like row covers, cloches, or cold frames to extend your harvest.
| Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| First 16° | Dec 10 | Dec 25 | Jan 6 | Jan 19 | Feb 5 | -- | -- | -- | -- |
| First 20° | Nov 24 | Dec 5 | Dec 13 | Dec 20 | Dec 27 | Jan 3 | Jan 12 | Jan 23 | -- |
| First 24° | Nov 6 | Nov 16 | Nov 24 | Dec 1 | Dec 7 | Dec 13 | Dec 19 | Dec 27 | Jan 7 |
| First 28° | Oct 24 | Nov 1 | Nov 7 | Nov 13 | Nov 17 | Nov 22 | Nov 27 | Dec 3 | Dec 12 |
| First 32° | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 22 | Oct 25 | Oct 28 | Nov 1 | Nov 6 |
| First 36° | Sep 24 | Sep 29 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 23 |
📍 Frost Dates for other nearby locations
- Buckley, WA 5.3 mi
- Palmer, WA 12.7 mi
- Landsburg, WA 16.4 mi
- Mc Millin Rsvr, WA 22.3 mi
- Cedar Lake, WA 22.5 mi
- Rainier Paradise Rs, WA 27.9 mi
- Snoqualmie Falls, WA 28.5 mi
- Kent, WA 28.8 mi
- Seattle Tacoma, WA 33.7 mi
- Packwood, WA 40.9 mi
Or enter a new zipcode:
Data is provided by the NOAA National Centers for Environmental Information.