Estimate asphalt mat cooling time or temperature with a calibrated Newton-cooling model using mix, air, base, wind, thickness, and stop temperature.

Choose a solve target, then complete the visible required fields marked with *.

Newton-cooling planning model: set the project stop target and calibrate the base cooling constant with field temperatures when available.

Related Calculators

Asphalt Temperature Formula

The calculator uses a simple wind-cooling rule of thumb. It estimates asphalt temperature from air temperature and wind speed, using degrees Fahrenheit and miles per hour as the base units.

Ta = Tair – (0.2 × W)
  • Ta = estimated asphalt temperature in °F
  • Tair = air temperature in °F
  • W = wind speed in mph
  • 0.2 = cooling coefficient in °F per mph of wind

If you leave air temperature blank, the calculator rearranges the formula:

Tair = Ta + (0.2 × W)

If you leave wind speed blank, the calculator rearranges the formula:

W = (Tair – Ta) / 0.2

The calculator can solve for any one missing value when you enter the other two. It also converts Celsius to Fahrenheit, km/h to mph, and m/s to mph before calculating, then converts the result back to your selected unit.

Wind Cooling Effect on Estimated Asphalt Temperature

The table below shows how much the calculator subtracts from air temperature at different wind speeds.

Wind Speed Cooling Adjustment Example with 80°F Air
0 mph 0°F 80°F asphalt
5 mph 1°F 79°F asphalt
10 mph 2°F 78°F asphalt
15 mph 3°F 77°F asphalt
20 mph 4°F 76°F asphalt

Temperature and Wind Unit Conversions

Conversion Formula
Celsius to Fahrenheit °F = (°C × 9/5) + 32
Fahrenheit to Celsius °C = (°F − 32) × 5/9
km/h to mph mph = km/h ÷ 1.60934
m/s to mph mph = m/s × 2.23694

Example Problems

Example 1: Find asphalt temperature

You enter an air temperature of 85°F and a wind speed of 12 mph.

Ta = 85 – (0.2 × 12)
Ta = 85 – 2.4 = 82.6°F

The estimated asphalt temperature is 82.6°F.

Example 2: Find wind speed

You enter an air temperature of 75°F and an asphalt temperature of 72°F.

W = (75 - 72) / 0.2
W = 3 / 0.2 = 15 mph

The estimated wind speed is 15 mph.

FAQs

Why can asphalt be hotter than the air in real life?

Sunlight can heat asphalt well above the air temperature because dark pavement absorbs solar radiation. This calculator does not model sun angle, cloud cover, pavement color, shade, or stored heat. It uses only air temperature and wind speed, so it is best treated as a rough wind-cooling estimate.

Why does the calculator reject a negative wind speed?

Under this simplified formula, asphalt temperature is calculated as air temperature minus a wind adjustment. That means the model assumes asphalt is equal to or cooler than the air. If your asphalt temperature input is higher than your air temperature input, solving for wind speed would produce a negative value, which is not physically meaningful for this model.

Can this calculator be used for paving or construction decisions?

Use caution. Actual pavement temperature depends on material, sunlight, ground temperature, moisture, and time of day. For paving, sealing, or construction specifications, direct surface temperature measurement is usually more reliable than a rule-of-thumb estimate.