NASA says the weather forecast for launch day shows an 80% chance of favourable weather conditions
13:26, 31 Mar 2026Updated 13:28, 31 Mar 2026
The Artemis II crew(Image: Getty Images)
The historic launch of NASA’s Artemis II moon mission is scheduled for April 1 at the earliest, with the mission countdown commencing yesterday (Monday).
But the launch of the much-anticipated flight will rely on the ideal weather conditions. Technical issues notwithstanding, sudden bad weather could result in the postponement of lift-off at any time.
NASA is working with weather officers on the US Space Force’s Space Launch Delta 45 to closely monitor the weather situation. The weather guidelines for NASA’s Artemis II test flight identify conditions to both safely roll out to the pad and launch the agency’s Space Launch System and Orion spacecraft.
These guidelines, set out below, include criteria for various meteorological conditions which weather teams will refer to as the mission counts down to getting underway. If other potential weather hazards exist beyond those in the guidelines, the launch weather team will report the hazardous condition to the launch director, who will determine whether launching would expose Artemis II to a weather hazard.
Currently, NASA says the weather forecast for launch day shows an 80% chance of favourable weather conditions. Cloud coverage and the potential for high winds mark the buiggest concerns facing the team.
According to launch director Charlie Blackwell-Thompson, NASA’s launch weather officer takes criteria like lightning, rain, and wind into account to give a percentage chance of how likely the launch can happen within the acceptable criteria.
“When we gave an 80% chance, that means there’s an 80% chance that we are going to be in an acceptable range across all of them. But if we’re in violation of any of them, then we’re going to wait it out.
“We have a two-hour launch window. That’s a wonderful thing, because when you look across the forecast, and I was looking at it just this morning, and you look at the winds, I think we’re going to be okay from a wind perspective.”
An 80% “chance of go” within that two-hour window means, she added: “I feel pretty good about our chances”.
Basic Weather Launch Criteria at the Pad for LiftoffTemperature
Do not initiate tanking if the 24-hour average temperature at both 132.5 feet and 257.5 feet is less than 41.4 degrees Fahrenheit.
Do not launch if the temperature at both 132.5 feet and 257.5 feet exceeds 94.5 degrees Fahrenheit for 30 consecutive minutes.
Do not launch if the temperature at both 132.5 feet and 257.5 feet drops below a defined temperature constraint for 30 consecutive minutes. The temperature constraints range from 38 degrees Fahrenheit to 49 degrees Fahrenheit, depending upon the wind and relative humidity. Higher wind and relative humidity result in a colder temperature constraint.
NASA astronaut and Artemis II Mission Specialist Christina Koch waves to the crowd(Image: AFP via Getty Images)
Wind
Do not initiate tanking if the 132.5-foot sustained wind is forecast to be greater than 37.5 knots or peak wind greater than 52.8 knots.
Do not launch if the peak liftoff winds exceed a range of 29 knots through 39 knots between 132.5 feet and 457.5 feet, respectively.
Do not launch through upper-level wind conditions that could lead to control problems for the launch vehicle.
READ MORE: NASA Artemis 2 launch set for April 1 as weather forecast issuedREAD MORE: NASA Artemis 2 Moon mission possible launch dates announced for April 2026Precipitation
Do not launch through precipitation.
Lightning
The Artemis II crew have made preparations for an April 1 launch(Image: Getty Images)
Do not initiate tanking of the core stage or interim cryogenic propulsion stage (ICPS) if the lightning forecast is greater than 20% within 5 nautical miles of the launch area during tanking.
Do not launch for 30 minutes after lightning is observed within 10 nautical miles of the flight path, unless specified conditions related to cloud distance and surface electrical fields can be met.
Do not launch if the flight path is within 10 nautical miles of the edge of a thunderstorm that is producing lightning until 30 minutes after the last lightning discharge is observed.
Do not launch if the flight path is within 10 nautical miles of an attached thunderstorm anvil cloud unless temperature, time since last lightning, and distance criteria can be met, and if within 3 nautical miles, maximum radar reflectivity criteria also are satisfied.
Do not launch if the flight path is within 10 nautical miles of a detached thunderstorm anvil cloud unless temperature, time since lightning and/or detachment, and distance criteria can be met, and if within 3 nautical miles, maximum radar reflectivity criteria also are satisfied.
Clouds
Do not launch if the flight path is within 3 nautical miles of a thunderstorm debris cloud for 3 hours, unless temperature, surface electric field, and radar reflectivity criteria can be met.
Do not launch if the flight path is within 5 nautical miles of disturbed weather clouds that extend into freezing temperatures and contain moderate or greater precipitation.
Artemis II crew member pilot Victor Glover gives a thumbs up after arriving at the Kennedy Space Center(Image: Getty Images)
Do not launch through a cloud layer that is within 5 nautical miles, greater than 4,500 feet thick, and extends into freezing temperatures, unless specific criteria related to radar reflectivity and cloud altitude can be met.
Do not launch if the flight path is within 10 nautical miles of cumulus clouds with certain distance and height criteria. There are additional caveats that could be met for clouds not reaching -5 degrees Celsius.
Do not launch through cumulus clouds formed as the result of or directly attached to a smoke plume, unless more than 60 minutes passed since detachment from the smoke plume.
Do not launch for 15 minutes if field mill instrument readings within 5 nautical miles of the launch pad equal or exceed +/- 1,500 volts per meter, or +/- 1,000 volts per meter, unless specific caveats related to clouds within 10 nautical miles of the flight path can be met.
Solar Activity
Do not launch during severe or extreme solar activity resulting in increased density of solar energetic particles with the potential to damage electronic circuits and make radio communication with the launch vehicle difficult or impossible.