A couple of years ago eastern Washington dry land wheat farmers had one of those rare years: a very good crop and high prices. World wheat prices had risen sharply and this rise had caused some folks on the plains to contemplate planting wheat. I did a comparison of precipitation between Lamar, Colorado and Connell eastern-washington-wheat-crop.
Comparison of rainfall by month between Lamar, CO and Connell, WA. Note that the difference on the precipitation scales.
What is noteworthy is that Lamar depends on summer rain for dry land wheat and the Connell area, and significant areas of winter wheat in eastern Washington, depends on winter precipitation. Although Connell gets less rain, the fact that it falls in the winter allows for soil moisture to accumulate more easily with the water coming when the evaporation rates are low. I will add that over a fairly large area of the eastern Washington dry land wheat area farmers plant every other year in order to build up soil moisture.
The other factor in comparing precipitation data was that southeast Colorado had much greater variability in precipitation. Another point was that it had been a long time since Lamar had a real low rain fall year. The last time Lamar had less than 10 inches of rain for the year was 1981.
So how does it look this year in Lamar.
January 0.38 0.00
February 0.44 0.19
March 0.82 0.59
April 1.41 2.02
May 2.27 0.22
June 2.24 1.19
July 2.39 0.29
A bad year to have planted wheat dependent on rain fall. Did not look bad at all in April, May and June were definitely not good, but the July. The last July rain was July 9. That was followed with no rain for the rest of the month and 17 days of over 100 F.