As our wet, cool spring draws to a close, it’s interesting to look back and compare our perceptions of what occurred with what DID occur.
Start with rain: it seemed really wet, right?
It was. In fact, we just finished the wettest March-May ever. The total precipitation of 18.68 inches easily bettered the old record of 16.19 inches set in 1993. This year’s total was an amazing 8.71 inches above the long-term average (“normal”) for the three-month period. The observations were recorded at OSU’s Hyslop Experiment Station on Highway 20 near Corvallis. Corvallis-area records go back to 1889.
Portland Airport also set a record for the three months, with 14.51 inches, barely beating the old record of 14.50 set in 1997. Records go back to 1940.
Temperatures seemed cool, right?
They were. But nowhere close to record-setting. The average temperature (49.7 degrees) was 0.8 degrees below normal, but this made 2012 only about the 40th coolest ever. This was mainly due to a warmer-than-normal April.
So what about summer? Is it ever going to come? Does the wet spring give us indications of what summer will be like? Will it be warm and dry?
Yes. But maybe not right away.
Looking back on Oregon spring-summer periods, there’s a pretty definite pattern. I would summarize it like this:
- We nearly always get several months of warm, dry weather every year. The only truly wet summer in recent decades was 1983. 1993 was wet all spring and clear through July, but dry afterward.
- Most of the time, when summer arrives late, it extends well into fall. For example, 1993’s wet March-July was followed by a very dry late summer and early fall.
- On the other hand, when warm, dry weather arrives early, it often leaves early. Case in point: 2005, when spring came early and warm, but wet weather arrived in August, followed by a wet September and October.
- Years with warm, dry springs are more likely to have hot summers; thus, don’t expect a scorcher this year!
Putting all that together, here’s what I come up with for a summer forecast:
- Mild conditions will continue for several more weeks, with some occasional rain.
- By early July, drier conditions will set in, and temperatures will warm up.
- Summer will be warm and dry but not excessively hot – more like an “average” summer than a hot one. In my humble opinion, an average Oregon summer is about as close to perfect as one can get, so I’ll be happy if this pans out.
- Early fall will be dry (September-October).
- In late October-early November we’ll have a very cold period, but it won’t be particularly wet.
In August, I’ll release my annual fall-winter forecast. In the meantime, enjoy the summer…when it arrives!