If you spent any time in the Pacific Northwest last spring, you know the drill. Everyone starts panic-buying sunscreen the second the thermometer hits 70, then immediately digs their North Face fleece out of the closet three hours later when the marine layer rolls in. Seattle weather May 2025 was exactly that kind of emotional rollercoaster, but with a weirdly dry twist that actually caught a lot of us off guard.
Honestly, we usually expect May to be that "bridge" month where the gray starts to crack. But 2025 didn't play by the usual rules.
While the rest of the country was dealing with massive storm cells and humidity, Seattle was sitting in this strange, parched pocket. It wasn't just "kind of dry." It was record-breakingly thin on the rain gauge. If you felt like you were watering your garden way more than usual for May, you weren't imagining it.
The Dry Spell: Seattle Weather May 2025 by the Numbers
Let's talk about the rain—or the lack of it. Sea-Tac Airport, our official weather yardstick, recorded only 44% of its normal precipitation for the month. That officially put May 2025 as the 12th driest May on record since they started keeping track in 1895.
Basically, we were living in a rain shadow of a rain shadow.
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Most of what we did get fell in one concentrated burst between May 11 and May 20. If you had outdoor plans during that window, you probably got soaked. But outside of those ten days? Bone dry. The Washington State Climate Office pointed out that this followed a super dry April, making the April-May stretch the 13th driest ever recorded in the state.
- Total Rainfall: Less than half of the 1991-2020 normal.
- Ranking: 12th driest in over 130 years.
- The "Big" Rain: Concentrated mostly around May 17-19.
It’s easy to forget that "Green Seattle" depends on these spring showers. By the end of the month, local meteorologists were already starting to whisper the "D" word: drought.
Temperature Swings and the 80-Degree Tease
Temperatures were a total mood. We started the month with a literal bang—May 1 saw temperatures climbing into the mid to upper 70s across central Puget Sound. It felt like summer had arrived six weeks early. But Seattle weather in May has a way of humbling you. By the next day, the onshore flow (that cold Pacific air we all love to hate) pushed back in, dropping us back to reality.
The month ended with another massive heat spike. On May 28, a ridge of high pressure built up, and suddenly everyone was at Alki Beach. Temperatures at Sea-Tac soared into the mid-80s.
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Nighttime Chills
Here is the weird part: even when the days were warm, the nights were unusually cold. Because the skies were so clear (no clouds to trap the heat), the temperature plummeted as soon as the sun went down.
In low-lying areas around the Sound and the Chehalis Basin, nighttime lows were consistently below normal. It was that classic "shorts during the day, parka at night" Seattle struggle. You’ve probably got a photo on your phone from that month wearing a tank top next to a fire pit because the 80-degree day turned into a 48-degree night in what felt like five minutes.
Why the Mountains Mattered
While we were enjoying the dry pavement in the city, the Cascades were telling a different story. The "snow drought" became a major talking point for the Washington State Climate Office.
Because April and May were so dry and warm, the mountain snowpack started melting way earlier than it should have. This is a big deal for our water supply and wildfire risk. When you look back at seattle weather may 2025, the lack of mountain moisture is actually the most significant long-term headline.
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We had a few late-season dustings at high elevations, but nothing that could offset the rapid melt. By May 31, the Pasco and Richland areas in Eastern Washington were hitting 95°F and 97°F. That heat eventually bled over the mountains, ending our month with a gusty, dry cold front that kicked up dust and reminded us that summer 2025 was going to be intense.
Planning for the Next Seattle Spring
So, what does this tell us for the future? If May 2025 taught us anything, it’s that the "June Gloom" is starting earlier or being interrupted by increasingly aggressive high-pressure ridges.
If you are a gardener, you can no longer rely on "May Gray" to keep your new starts hydrated. You need to have your irrigation ready by May 1. The trend is leaning toward drier, sharper transitions from spring to summer.
Specific Actionable Insights for Seattle Residents:
- Gardeners: Mulch earlier in the year (late March/early April) to preserve soil moisture, as May is becoming increasingly unreliable for rain.
- Hikers: Expect trails to open earlier due to rapid snowmelt, but be prepared for high creek levels in May and very dusty conditions by early June.
- Energy Use: If you don't have AC, May is now the month to service your fans or install heat pumps. The late-May spikes in 2025 were a clear warning shot for the heatwaves that followed.
Keep your layers handy. Even in the driest, warmest May on record, the Pacific Ocean is always waiting to send a 50-degree breeze through your open window the second you get comfortable.
Next Steps for Your Spring Prep:
Check your outdoor spigots and irrigation timers before May 1st this year. Given the patterns we saw in 2025, you'll likely need to supplement your lawn and garden much earlier than the old "wait for July" rule suggests. You should also audit your home's cooling situation now; those 80-degree spikes in late May are becoming a consistent feature of the new Seattle spring.