Marston Lake
# Marston Lake

Marston Lake is a reservoir in Denver, Colorado. It is owned by Denver Water and was completed in 1902. The reservoir sends water to the Marston treatment plant, and from there the water is distributed to Denver residents.

The reservoir receives water from the South Platte River. The river receives water from the Colorado Western Slope through a transmountain diversion via the Roberts Tunnel.

## Climate

According to the Köppen Climate Classification system, Marston Lake has a cold semi-arid climate, abbreviated "BSk" on climate maps. The hottest temperature recorded at Marston Lake was 104 °F (40 °C) on July 18, 1998, while the coldest temperature recorded was −19 °F (−28 °C) on December 31, 2014.

Climate data for Marston Filter Plant, Colorado, 1991–2020 normals, extremes 1998–present :

| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Record high °F (°C) | 72 (22) | 77 (25) | 81 (27) | 84 (29) | 96 (36) | 100 (38) | 102 (39) | 104 (40) | 97 (36) | 87 (31) | 80 (27) | 73 (23) | 104 (40) |
| Mean maximum °F (°C) | 65.5 (18.6) | 66.7 (19.3) | 74.5 (23.6) | 78.4 (25.8) | 85.1 (29.5) | 95.2 (35.1) | 96.6 (35.9) | 94.4 (34.7) | 91.8 (33.2) | 82.3 (27.9) | 74.4 (23.6) | 65.5 (18.6) | 97.7 (36.5) |
| Average high °F (°C) | 45.8 (7.7) | 46.5 (8.1) | 54.6 (12.6) | 60.1 (15.6) | 69.0 (20.6) | 80.8 (27.1) | 86.4 (30.2) | 85.0 (29.4) | 77.2 (25.1) | 64.2 (17.9) | 53.4 (11.9) | 45.4 (7.4) | 64.0 (17.8) |
| Daily mean °F (°C) | 32.6 (0.3) | 33.4 (0.8) | 41.3 (5.2) | 47.3 (8.5) | 56.4 (13.6) | 67.1 (19.5) | 73.0 (22.8) | 71.3 (21.8) | 63.0 (17.2) | 50.4 (10.2) | 40.6 (4.8) | 32.8 (0.4) | 50.8 (10.4) |
| Average low °F (°C) | 19.3 (−7.1) | 20.3 (−6.5) | 28.1 (−2.2) | 34.5 (1.4) | 43.8 (6.6) | 53.4 (11.9) | 59.5 (15.3) | 57.5 (14.2) | 48.7 (9.3) | 36.7 (2.6) | 27.7 (−2.4) | 20.2 (−6.6) | 37.5 (3.0) |
| Mean minimum °F (°C) | 0.0 (−17.8) | −0.3 (−17.9) | 12.1 (−11.1) | 20.5 (−6.4) | 29.9 (−1.2) | 44.1 (6.7) | 53.1 (11.7) | 49.1 (9.5) | 38.3 (3.5) | 21.8 (−5.7) | 11.7 (−11.3) | −1.7 (−18.7) | −7.6 (−22.0) |
| Record low °F (°C) | −8 (−22) | −16 (−27) | −6 (−21) | 6 (−14) | 15 (−9) | 31 (−1) | 49 (9) | 42 (6) | 29 (−2) | 7 (−14) | −6 (−21) | −19 (−28) | −19 (−28) |
| Average precipitation inches (mm) | 0.48 (12) | 0.67 (17) | 1.19 (30) | 2.07 (53) | 2.73 (69) | 1.87 (47) | 2.05 (52) | 1.85 (47) | 1.26 (32) | 1.04 (26) | 0.74 (19) | 0.61 (15) | 16.56 (419) |
| Average snowfall inches (cm) | 6.3 (16) | 6.2 (16) | 5.4 (14) | 4.1 (10) | 0.8 (2.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 1.7 (4.3) | 3.7 (9.4) | 5.9 (15) | 34.1 (86.7) |
| Average precipitation days (≥ 0.01 in) | 4.1 | 4.4 | 5.1 | 7.2 | 9.8 | 7.7 | 8.3 | 9.0 | 6.0 | 5.1 | 3.7 | 3.9 | 74.3 |
| Average snowy days (≥ 0.1 in) | 3.3 | 4.0 | 3.3 | 1.9 | 0.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.9 | 2.0 | 3.4 | 19.3 |
| Source 1: NOAA ||||||||||||||
| Source 2: National Weather Service (mean maxima and minima 2006–2020) ||||||||||||||
