Bryan Carlson is an USDA-ARS Ecoinformaticist. He leads data management and data engineering efforts as well as codes decision support tools and biophysical models.
A very dry spring
If you have a hunch that this has been a very dry spring, then we may have some data to back you up. According to Bob Barry, a technician for CAF, "we are having the driest March + April + May since 1930, and, possibly since 1893." The total precipitation for all of March through May was only 1.2 inches; a far bit less than our average 5.3 inches (Figure 1).
Figure 1: March, April, May total precipitation (inches) for each year from 1930 to 2021. In this range, 2021 is the driest spring.
Bob is in charge of a weather station at our Palouse Conservation Field Station near Pullman, WA and manages a dataset that stretches back to 1893. That is not a typo, by the way, weather was first measured there in the 1800’s!
Bob cautions that the early data gets difficult to interpret. He states:
"There are some inconsistencies in the weather data. The data from National Weather service and the handwritten weather records that go back to 1893 did not always agree. I have relied on hand written records whenever possible. Also, prior to 1930 they recorded snow and rain separately and the snow was not included in the total precipitation."
The discrepancy in recording daily precipitation prior to 1930 causes some uncertainty when concluding that this is the driest spring on record. The year 1924, for example, had only 0.5 inches of rain but had 4.5 inches of snow. Because converting snow depth to water-equivalent with limited information results in a rough estimate, it is difficult to compare the numbers. If we do some hand-waving then 1924 may hold the crown as the driest spring at 1 inch of precipitation.
Data issues aside, this has been a far drier spring than is usual. Bob concludes that "1924 was possibly the driest spring on record. Because of the inconsistencies of very old weather data it makes it questionable which spring is actually the driest, 2021 or 1924. No matter how you look at it, we are having a very dry spring."
For related data, see PCFS Weather Station: https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USC00456789/detail