From the webpage:
This directory contains hourly weather dumps. The files are compressed using Zstandard compression (.zst). Each file is a collection of JSON objects (ndjson) and can easily be parsed by any utility that has a JSON decode library (including Python, Java, Perl, PHP, etc.) Please contact me if you have any questions about the file format or the fields within the JSON objects. The field “retrieved_utc” is a field that I added that gives the time of when the data was retrieved. The format of the files is WEATHER_YYYY-MM-DD-HH (UTC time format).
Please consider making a donation (https://pushshift.io/donations) if you download a lot of data. This helps offset the costs of my time collecting data and providing bandwidth to make these files available to the public. Thank you!
If you have any questions about the data formats of the files or any other questions, please feel free to contact me at jason@pushshift.io
A project of pushshift.io, the homepage of which is a collection of statistics on Reddit posts.
Looking at the compressed files for today (24 January 2019), the earliest file is dated Jan 24 2019 AM and tips the scales at 35,067,516 bytes. Hourly files, running between 72,272,568 and 65,989336 bytes. Remembering these files are compressed so you need a lot of space or work with them compressed.
The perfect data is your boss is a weather freak. Be sure to mention the donation link to them.
Enjoy!