Spring is unpredictable across the middle of the country at that latitude, as day to day weather is controlled by interaction of warm, soggy Gulf air masses and cold, (usually) dry air masses coming down through the Great Plains.
We can have temperatures in the 60s and 70s as early as late February, only to have that followed by snow or ice storms as late as mid-April. As cold fronts come through, rain can be quite heavy as an alternative to snow, and getting into April it will be the start of tornado season, although the really big storms are more toward late April to June, when there is more heating of the ground and wet air from daily sunlight.
Weather can be quite different at Lake of the Ozarks than the same time down in the SW corner of the Ozarks (S Central Missouri, NW Arkansas, NE Oklahoma). March and April are in our regular "camping" season, but we have cancelled campouts in March because there was too much ice and snow for safe travel, and postponed in April and May because severe storms were forecast for the originally planned dates (reliable forecasts are 2-3 days out, except that some systems slow down and arrive 12-36 hours late).
Tulsa District Corps of Engineer facilities (Oklahoma, N Texas) do not usually open until April 1st, when volunteer host and caretakers start showing up. I don't know the schedule for Arkansas. State Parks are usually open year round in Missouri, Oklahoma and Arkansas, unless closed by flooding. Commercial campgrounds vary; the one we use in March at Grand Lake is open all winter, others may not open until April. The latest opening we've encountered has been the week before Memorial Day; that was a primarily seasonal park.
Average temperatures for spring months are not as useful here as they might be in parts of the country with more stable weather. You need also look at record lows.
I would say "come on down" but keep your options open, you may want to move to avoid a storm. This time of year I prefer to visit East Texas or the Texas Hill Country when thinking long stays. In the Ozarks it is a matter of looking a few days ahead for planning short campouts.
Tom Test
Itasca Spirit 29B
