| Geyser | 1983-08-31 |
|---|---|
| Echinus | 1115 ie, 1150, 1225 ie, 1307, 1503 |
| Fan-Norris | 1800 |
| Graceful | 1444:25, 1453:30 |
| Incline | 1402 |
| Pearl | 1237 |
| Pinto | 1800 |
| Steamvalve Spring | 0825, 1059 |
| Values for Old Faithful Area | 1983-08-31 |
|---|---|
| Astronomical Twilight Begin | 04:59 |
| Nautical Twilight Begin | 05:38 |
| Civil Twilight Begin | 06:14 |
| Sunrise | 06:44 |
| Sunset | 20:02 |
| Civil Twilight End | 20:32 |
| Nautical Twilight End | 21:09 |
| Astronomical Twilight End | 21:47 |
| Moon Illumination | 52.45% |