Artemis I Launch Forecast: Will the Weather Cooperate for America's Return to the Moon?

Update Monday morning: NASA has scrubbed the launch of Artemis I due to technical issues. Launch is rescheduled to Friday. Stay tuned!

 FastCast-Monday, Aug. 29 to Friday, Sep. 2:

Another hot stretch is ahead for Western Washington. Mostly sunny conditions are expected all week, with a return of more clouds by Friday. Monday will be mostly sunny, with highs in the low 80s (upper 70s near the water). Tuesday and Wednesday will be the hottest days, with temperatures climbing into the upper 80s to near 90. The hottest day will be Wednesday, when the Lowlands have the best chance of reaching the low 90s. That will be most likely in the foothills and Olympia area. Thursday will be slightly cooler, with highs reaching the mid 80s, potentially the upper 80s in the normal hot spots. Friday will bring the return of partly cloudy conditions and onshore winds, with highs dropping to the low 80s. Lows all week will remain in the upper 50s, a sign that we are getting closer to fall. In Eastern Washington, expect another week of highs in the mid 90s to low 100s, hottest in the Columbia Basin. Keep reading below to find out if the weather is expected to cooperate for Monday morning's historic NASA Artemis I launch in Florida!

Watch live coverage: NASA YouTube Livestream

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Continue reading the full blog below!

On Monday, August 29th, from 8:30 to 10:30 AM Eastern Time (5:30-7:30 AM Pacific), the launch window is open for NASA's historic Artemis I launch, which will send NASA's largest rocket ever into space, eventually sending the Orion spacecraft on a 42-day orbit of the Moon. The Artemis I mission paves the way for America to return to the Moon for the first time in over 50 years...so it's quite a big deal! (Image: NASA)

We will use the two highest-resolution models available, the HRRR and NAM. The HRRR forecast for precipitation at the beginning of the launch window is below.

The Kennedy Space Center is located on Cape Canaveral, the area of land sticking out into the Atlantic Ocean between Palm Bay and Daytona Beach. The HRRR forecast shows showers getting quite close to Cape Canaveral, which could delay or cancel the launch. NASA rules state that launches can't happen through precipitation or within a certain distance of cumulus clouds that may contain lightning.

The NAM forecast also shows some showers near Cape Canaveral.

The NAM has showers closer to the coast moving toward Cape Canaveral. Showers and thunderstorms are often the biggest threat to launch, and it appears they will be a big factor with Artemis I.

Perhaps an even bigger threat to launch will be clouds. NASA rules state that if the flight path is within 5 nautical miles (5.7 mi) of clouds with freezing temperatures and/or moderate to heavy precipitation, launch must be delayed or canceled. Additionally, if the flight path is within 3 nautical miles (3.5 mi) of a thunderstorm for 3 hours, launch can't occur. 

Learn more about NASA's Artemis I launch rules by clicking here.

The HRRR forecast for cloud cover at the beginning of the launch window is below.

The HRRR shows 100% cloud cover at Cape Canaveral. This doesn't necessarily mean that it's a no-go for launch, but clouds could cause some problems. The thickness of the cloud layer and presence of large and tall cumulus clouds is what will delay or cancel the launch.

The NAM forecast below differs slightly.

The NAM forecast shows Cape Canaveral between areas of cloud cover, which is good and bad. It is good because it may help launch, but it is bad because breaks in the clouds can fuel showers and thunderstorms, which will delay or cancel launch.

As usual, it will come down to a last-minute decision. If launch is canceled on Monday, NASA says it can be rescheduled to Friday, September 2nd or Monday, September 5th (Labor Day).