Onion Springs Overflow Camping Area
Campground · Yosemite corridor
Onion Springs Overflow Camping Area sits at 5679 feet in the Yosemite corridor's high Sierra. A small overflow facility, it offers quieter camping than the main Yosemite valley campgrounds.
Wind averages 7 mph over the rolling 30 days but gusts to 20 mph in afternoon hours. Morning calm typically holds until mid-day. Expect cooler nights at elevation; the 30-day average temperature is 43 degrees Fahrenheit. Afternoon thermal wind is the dominant pattern.
Over the last 30 days, Onion Springs Overflow has averaged a NoGo Score of 16.0 with temperatures holding near 43 degrees Fahrenheit and wind at 7 mph average. The week ahead will show whether the typical spring pattern holds or shifts cooler and windier. Watch the chart for afternoon wind spikes and crowding surges tied to regional holiday weekends.
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About Onion Springs Overflow Camping Area
Onion Springs Overflow Camping Area is a small overflow facility at 5679 feet elevation on the eastern flank of the Sierra Nevada, situated within the Yosemite corridor. It serves as relief camping when Yosemite Valley and Highway 120 corridor sites fill to capacity. The site sits roughly 40 minutes from the Highway 120 junction at Crane Flat and benefits from lower popularity (base popularity 0.3) compared to major Yosemite campgrounds. Access is via Highway 120 from the west or Highway 395 from the east; the location is best approached during shoulder seasons when the main valley corridor is moderately full but not completely saturated.
Spring conditions at Onion Springs Overflow typically track the broader Sierra Nevada pattern: the 30-day average temperature is 43 degrees Fahrenheit with wind averaging 7 mph and peaking at 20 mph. Crowding averages 12 on the rolling 30-day window, reflecting its status as an overflow site. Late April through early June sees afternoon thermal winds funnel through the corridor as valley temperatures rise; mornings are calm and often cold below freezing. By late summer, afternoon wind becomes pronounced and consistent. Winter snowpack can linger at this elevation into late May; plan around remaining snow on access roads. The NoGo Score has averaged 16.0 over the rolling 30 days, indicating moderate but not severe conditions.
Onion Springs Overflow suits campers seeking lower crowds and a quieter alternative to main Yosemite facilities. Experienced Sierra campers use it as a base for day trips into the high country or as a strategic overflow stop when Highway 120 camps are full. The site's low popularity means parking pressure is minimal even on busy weekends. Plan for afternoon wind by pitching tents with windward sides facing north or northeast. Water availability and amenities are basic; bring supplies from Lee Vining or Groveland. The 30-day max wind of 20 mph is manageable but warrants secure tent setup and awareness of exposed ridge exposure if exploring nearby.