I bet the library of Congress has millions of US weather maps.
I found the following clue in the 1895 US Weather Bureau report, page 70.
“Three million one hundred and forty-eight thousand eight hundred and ninety-five weather maps were issued during 1895… 10,680 daily weather maps…the quality of these maps as to appearance and accuracy has been well maintained… The expense of lithographing the weather map, as is done in Washington…”
Search books.google.com for “report chief weather bureau”. Download the free e-books as a pdf.
If any readers live near LOC, ask one to take a trip and do a little research for you.
The NOAA Library in Silver Spring, MD is a treasure trove of actual weather records, assuming they have not thrown out the records and assuming they still allow public access.
Real Science 
Look in the trash cans of any University …
You might put that question to Charles Anderson (see his blog, objectivistindividualist.blogspot.com for his e-mail address).
Maybe various department of agriculture’s records? Forestry?
I bet the library of Congress has millions of US weather maps.
I found the following clue in the 1895 US Weather Bureau report, page 70.
“Three million one hundred and forty-eight thousand eight hundred and ninety-five weather maps were issued during 1895… 10,680 daily weather maps…the quality of these maps as to appearance and accuracy has been well maintained… The expense of lithographing the weather map, as is done in Washington…”
Search books.google.com for “report chief weather bureau”. Download the free e-books as a pdf.
If any readers live near LOC, ask one to take a trip and do a little research for you.
Got two more hits.
Search books.google.com for the exact phrase “Monthly Weather Review”. I chose 19th century under “Search Tools” to verify it goes way back.
Search books.google.com for the exact phrase “Statistical Abstract of the United States”
We can crowdsource the data entry if need be. That’s original data
One of the earliest I have seen – Figure 20 Page 25 here.
Click to access climate-assessment-1981-1990.pdf
Other state of the climate assessments (starting with 1981-1990 and then annual from 1990 onward) here on this page. PDFs only.
http://www1.ncdc.noaa.gov/pub/data/cmb/bams-sotc/
Here are two:
Taken from http://www.dvfu.ru/meteo/library/1995316391.pdf
and http://bit.ly/1eYAJhF (page 258)
The NOAA Library in Silver Spring, MD is a treasure trove of actual weather records, assuming they have not thrown out the records and assuming they still allow public access.