Will it freeze in Truckee tonight? A plain guide to frost, black ice, pipes and equipment, from a Truckee excavation foreman who works outside in it.
Check tonight's low first. The Truckee weather forecast shows the overnight low from a blend of eight models, checked against real station readings. A low of 32 degrees Fahrenheit or colder means a freeze. See the published forecast accuracy for how the blend has done against the Truckee airport station.
Truckee sits at about 5,817 feet in a basin. On clear, calm nights the ground loses heat to the sky and the coldest air drains downhill and settles on the valley floor and along the Truckee River. That is why the low can come in several degrees under the daytime forecast, and why a frost can show up here weeks before it reaches lower elevations. Clouds, wind and a wet snowpack all hold temperatures up; clear skies and dry air let them fall.
| Overnight low | What to expect |
|---|---|
| 33 to 36 F | Frost possible on grass, car windows and rooftops under clear, calm skies. |
| 32 F or below | Freeze. Tender plants, hoses and exposed irrigation are at risk. Wet pavement can ice. |
| 25 to 31 F | Hard freeze for gardens. Black ice on bridges, shade and wet roads in the morning. |
| Around 20 F or colder for hours | Pipes in crawl spaces and exterior walls are at risk. Protect plumbing. |
Road surface can freeze when the air reads a few degrees above 32. Bridges, shaded corners and the river canyon freeze first, and melt-and-refreeze cycles make ice most likely between midnight and mid morning. If the low is near or below freezing, assume ice, slow down and leave extra room. For the climb over the summit, see Donner Summit road conditions.
Crews and equipment owners get caught by the first hard freezes. Plug in block heaters where fitted, use winter-grade fluids, park machines on dry ground or planks so tracks do not freeze down, protect water lines and batteries, and follow the manufacturer's cold weather procedures. For go or no-go calls on crew days, see the crew weather page. Equipment questions go through E Kerr LLC equipment rental.
Check the overnight low on the Truckee forecast at errolkerr.com/truckee-weather. A low at or below 32 degrees Fahrenheit means a freeze. Truckee sits at about 5,817 feet in a cold air basin, so clear, calm nights run colder than the daytime forecast suggests, and the valley floor and river corridor are usually coldest.
Road surfaces can freeze even when the air reads a few degrees above 32. Bridges, shaded corners, the Truckee River canyon and any wet pavement freeze first, mostly between midnight and mid morning after a clear night or after daytime melt refreezes. When the low is near or below freezing, assume ice on the morning drive.
Let faucets on exterior walls and in unheated spaces drip, open cabinet doors under sinks, disconnect and drain hoses, and keep the heat on in vacant buildings. Pipes are most at risk when lows stay below about 20 degrees for several hours, especially in crawl spaces and outside walls.
Plug in block heaters where fitted, use the right winter diesel and fluids, park machines on dry ground or planks so tracks do not freeze down, drain or protect water lines, and cover batteries. Check with the equipment manufacturer for exact cold weather procedures.
errolkerr.com/weather shows an eight model blend, 22 live Caltrans cameras and the Kerr Storm Tracker, and errolkerr.com/weather#accuracy publishes its own forecast error against the Truckee airport station.