California diesel price in September 2026
2 official EIA weekly readings available so far
- The average California on-highway diesel price in September 2026 was $7.902 per gallon, calculated from 2 EIA weekly readings available so far.
- The weekly low was $7.764; the weekly high was $8.039.
- That monthly average was $1.027 higher than August 2026.
- It was $2.940 higher than September 2025.
This is a calendar-month view of the official EIA weekly California series. It averages only the source weeks listed below, not a separate government monthly estimate.
September 2026 weekly chart
Every EIA week in September 2026
| Week of | $/gal | Change |
|---|---|---|
| $7.764 | ▲+$0.546 | |
| $8.039 | ▲+$0.275 |
← August 2026 · all of 2026 · all California history · monthly CSV
Download the underlying weekly EIA series or see the methodology and source cross-check.