Average Temperature Outlook for CLE ELUM (issued in January 2015) suggests that during Feb-Mar-Apr 2015:

There is a 99% chance that the average 3-month temperature will be within the range of 34.9 and 44.7 Deg F,.

There is a greater ( 64.0%) chance that the temperature will be higher than the climatological median* of 30.3 Deg F, and a lesser (36.0%) chance that the temperature will be lower than the climatological median*.

*For the climatological reference information, the median statistic is reported. The median value means that during the present climatological reference period (1981-2010), half of the years (50%) temperature was greater than the median and in the other half (50%) less than that.