Spring - April / May / June
Spring comes a bit late to the high desert of southern Idaho. At Craters of the Moon, winter snowpack may last into early May and often the loop road is not open for use until mid-April. April and May can still see snow storms that temporarily close the loop drive, snow on many of the trails, and closure of the lava tubes or caves due to hazardous ice. Temperatures can vary from warm to cold during the daytime to cold during the night. Camping facilities are limited at this time and services limited. From mid to late-June the wildflower bloom at the monument is at its peak. Longer hikes into the wilderness are recommended during this period of moderate temperatures.