Helena is located in west-central Montana in the foothills of the Big Belt Mountains on the eastern slope of the Continental Divide, 48 miles north-northeast of Butte, Montana. Helena is located midway between Glacier and Yellowstone national parks and fertile valleys lie to the north and east. The Missouri River flows northward nearly 10 miles east of the city.
Helena has a modified continental climate with warm, dry summers and moderately cold winters. Mountains located to the north and east of the city sometimes deflect shallow masses of arctic air to the east, but at times cold air can be trapped in the valley for days. During the coldest period, from November through February, temperatures sometimes drop to 0° F or below. Summer temperatures are usually under 90° F and the mountains account for marked changes in temperature from day to night. April through July is the rainy season, while late summer, fall, and winter are quite dry.
| 14 square miles (2000) | |
| 4,090 feet above sea level | |
| January, 20.2° F; July, 67.8° F; annual average, 44.0° F | |
| 11.32 inches |
