More often than not you can expect weather in Yellowstone National Park in the time of August is 11. Average highs are typically 22 and lows being 4. The table below has further info:
| Month | Degrees Celsius |
|---|---|
| Temperature | 11 |
| High Temperature | 22 |
| Low Temperature | 4 |
Useful Links: Yellowstone National Park Weather: Average Weather & Yearly Climate