Lhasa can be visited any time of the year. Winter months (November-March) are cold. July and August is the monsoon, so it is rainy. July, August, and the first week of May are the busiest times in Lhasa.
For the Friendship Highway, the best months are April-June and September-October.
For the Everest trek and bicycle tour, the best months are May-July and September-October.
| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | |
| High (°F) | 44 | 48 | 53 | 60 | 66 | 72 | 71 | 70 | 67 | 61 | 52 | 45 |
| Low (°F) | 13 | 19 | 26 | 33 | 41 | 48 | 50 | 48 | 45 | 34 | 23 | 15 |
| Precip (in) | .00 | .00 | .10 | .20 | 1.10 | 2.90 | 4.70 | 4.80 | 2.30 | .40 | .10 | .00 |