Ethereum Gas Price Chart

from 18 Sep '20 10:30 UTC
Etherscan.io Gas Tracker API
from 23 Jun '20 09:30 UTC to 18 Sep '20 10:00 UTC
Etherchain.org Gas Price Oracle
from 15 Jun '20 10:00 UTC to 23 Jun '20 09:00 UTC
ETH Gas Station

UPDATE 29 Dec '20
+Color mode added. (Day/Night and Rainbow)
The time zone used depends on your location. Check bottom of the snapshot image.
18 Sep '20
+Changed gas price data source.
Now using Etherscan.io Gas Tracker API from 18 Sep '20 10:30 UTC, since old data source (Etherchain.org Gas Price Oracle) often returns questionable value like "6 gwei".
+Dark mode added.