“Two seasons—winter and August”

“This place has only two seasons—winter and August” (or “winter and the Fourth of July”) is said of any place that has a very long winter season. “We have but two seasons—winter and the Fourth of July” was said about St. Paul, Minnesota, in 1893. “Eldora had two seasons, winter and August” was said about Eldora, Colorado, in 1899.
 
Similar sayings include “There are only two seasons in the North—winter and road construction” and “Minnesota has two seasons—winter is coming and winter is here.”
 
 
Chronicling America
13 June 1893, St. Paul (MN) Daily Globe, “In the Nineties,” pg. 8, col. 3:
Warm weather of the Fourth of July series was what St. Paul denizens had yesterday, and so hot that the chronic grumbler, whose bones are his weather indicator, announced to his neighbor that we have but two seasons—winter and the Fourth of July.
 
15 March 1899, Colorado Springs (CO) Gazette, “Items from Eldora,” pg. 7, col. 3:
One young man in writing to his parents this week said that Eldora had two seasons, winter and August.
 
25 August 1906, Duluth (MN) News Tribune, “Caught on the Run,” pg. 6, col. 3:
One of the latest forms of joke about Duluth’s climate has just come to the light of day. From time immemorial it has been said that the stranger’s comment was that “the coldest winter he ever spent was a summer in Duluth,” and another bon mot was and is to the effect that Duluth has “two seasons—winter and August.”
 
7 February 1907, Milford (IN) Mail, “From North Dakota,” pg. 1, col. 5:
I think Wash Harriman told the truth when he said “Dakota had only two seasons—(winter and July.”)
 
HathiTrust Digital Library
11 February 1920, The Gas Record, “Gas for House Heating,” pg. 11, col. 2:
With the except, perhaps, of cities in the northern part of the country where there are but two seasons—Winter and August—there is a growing interest in the subject of gas as a home heating fuel.
 
16 May 1935, Moorhead (MN) Daily News, “Continued Cool,” pg. 2, col. 1:
The old gag that North Dakota has only two seasons, winter and the Fourth of July, is brought out and dusted off.
   
Google Books
Fair and Warmer:
The problem of weather forecasting and the work of the United States Weather Bureau

By Joseph Gaer
New York, NY: Harcourt, Brace and Company
1939
Pg. 10:
And then, of course, there was the Yankee from down East for whom there existed only two seasons in any year — winter and the Fourth of July.
 
Google News Archive
6 November 1957, Nashua (NH) Telegraph, “Around the Town,” pg. 14, col. 5:
They say some parts of New York state have only two seasons, winter and July and based on that trip, we believe them.
   
Google Books
The Modern Handbook of Humor
By Ralph Louis Woods
New York, NY: McGraw-Hill,
1967
Pg. 372:
Maine has two seasons: Winter and August.