About VisitWhen
VisitWhen answers one question — "when should we go?" — with official data instead of guesses, for every US national park.
The National Park Service publishes monthly visitation counts for every park. NOAA publishes 30-year weather normals. Daylight is just math. Nobody had joined the three into a straight answer — so travel advice about timing stayed anecdotal ("summer is busy", "spring is nice") while the actual numbers sat in government databases.
VisitWhen computes the join: every month of every park scored by one public formula over crowds, comfort and daylight. When the data says a famous park is at 5% of its peak with hikeable weather, you'll see it. When "off-season" actually means the road is closed, you'll see that too.
VisitWhen is built and maintained by Caslon Media. It is not affiliated with, or endorsed by, the National Park Service or NOAA — we compute over their public data and always link the sources.
Parts of VisitWhen's text are drafted with AI assistance. The numbers are not: every visitation figure, weather normal and month score is computed from the cited NPS and NOAA data by the formula on the methodology page.