It sure has been warm and dry this May…but if you haven’t been keeping close track of the numbers, you may be shocked to find out just how warm it truly is. At least in The Dalles, it’s been MUCH warmer than the warmest May on record. That was in 1958, when it was 65.7 degrees F. That number is 4.9 degrees above the modern 30-day averages, but 5.6 degrees above the 1951-1980 May average. Spring is gradually getting warmer in our climate, even if the change hasn’t been as dramatic as some other times of the year.

But this May has felt far more like a summer month than a spring one. As of the 24th of the month, our temps are running an astounding 8.3 degrees above average, at 68.2 degrees F. Not only does it blow the old record out of the water, but it’s warmer than both a normal June and a normal September. (September has slightly warmer daytime temps, but cooler nights result in mean temps about 1 degrees F cooler than June.).

The running average high temp is currently at 81.8 degrees, and 15 out of 24 days have been 80 or warmer. In 1969, 1992 and 1993 there were 16 such days; all we need is for Sunday and Monday to be above 80 to set a new record for the month.

The funny thing is that we haven’t seen any super-hot patterns with high temps in the 97-102 range; the best we could muster this month was 94. It’s just been consistently mild or warm or hot the entire time since late April. There hasn’t been a single day since April 23, where the daily MEAN temperature (average of the high and low) was cooler than normal for the date.

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The weather has also been extremely DRY this past month. Since April 16, only 0.03″ of rain have fallen. That’s even drier than a normal July or August is! All this dry and warm weather is beginning to take its toll on the landscape; the hills in the eastern Gorge look about as dry and “summery” as they normally do in the middle of June.

I was thinking that with all this warm/dry weather, we might see some hints of the orchard cherries ripening now, but most are still green. There were a FEW branches that looked kind of yellowish, though. I still think the seasonal workers will be in town within another week or so, though.

Oh yeah…with so little rain and everything beginning to get dry? There have already been a few small wildfires east of the Cascade crest. My feeling is that if we don’t get significant rain in the next couple weeks, then the whole month of June could end up being a tinder box, especially if we see any major lightning. As for drought…I think the latest SNOTEL graphic tells it all:

Southeastern Oregon is already experiencing drought conditions, due to the combination of a dry winter and now an unusually dry 2nd half of spring. It’s very possible that the drought spreads northward and westward, later this summer. It’s important to bear in mind that Pacific Northwest droughts are triggered mainly by dry winters, not long dry summers as some people believe. Winter is when most of our rain and snow are available; too many dry spells and both the water table and snowpack suffer. Surface vegetation may look extremely dry after a couple months in the summer with no rain. But it takes a longer time for the deep soil and the water table, to dry out – and thus, cutting out the winter rains is key.

It’s now turned cooler over the Pacific Northwest! The last week of May will not be hot like we’ve seen recently. A strong marine push took over on Friday, and now Saturday we’re in a cooler and drier airmass. Things could warm up a little bit tomorrow and Memorial Day Monday…but then another push of cool air from the northwest comes in the middle of next week. Unfortunately it won’t bring much chance of rain, save a few sprinkles west of the mountains if marine clouds are thick enough.

After all this warm, summer-like weather? The switch to cooler air, clear skies, and low dewpoints will feel crisp and refreshing…almost like a taste of Fall but without the longer nights. I wouldn’t be surprised to see overnight temps in the 40s again, by the middle of next week. It will be an ironic reminder, on the eve of “meteorological summer,” that it’s technically still springtime in our climate.