Reefer Hot Days and Fuel: What NOAA Normals Say About July

Why this matters. Two reefer loads leave on the same day at the same rate per mile. One loads in Phoenix, the other in Chicago. By July, the air around the first trailer is at or above 90 F on 30.8 days of the month. Around the second it is on 6.5. The unit works harder in one place than in the other, and the diesel bill shows it. A little weather arithmetic makes the difference visible before the load is booked.

How many hot days in a typical July

The count is days with a high of 90 F or more. Here are eight cities from our list of 44.

Source: NOAA NCEI, variable MLY-TMAX-AVGNDS-GRTH090. Phoenix also has 28.5 days at 100 F or more in a typical July. The share column is our reading of the count out of 31.

From hot days to diesel dollars

The page has no reefer fuel rate and neither does this article. The extra gallons per run hour on a hot day is your number, from your own fuel logs. To show the arithmetic, here are invented unit figures.

Example data: your reefer trailer spends 10 days of July in or near a city. On a hot day the unit runs 12 hours and burns an extra 0.3 gallons per run hour. Diesel costs $6.20 a gallon.

Expected days are rounded for display; dollars use the unrounded figure. The unit figures are invented. Replace them with yours.

Phoenix against Chicago is a $174.96 difference over 10 days on the same invented unit. Whether your trailer really burns 0.3 gallons more on a hot day is something only your logs can answer, and it is the number to pin down first.

The cold side is a different problem

Winter does not load a reefer the way July does. It puts freight at risk of freezing, and that matters for produce, liquids and anything that must not drop below a set temperature. NOAA also counts days with a low of 32 F or less.

Source: NOAA NCEI, variable MLY-TMIN-AVGNDS-LSTH032.

The cities flip. Chicago is a light July city and a heavy January city. Phoenix is the opposite. A lane that touches both kinds of place in one year needs a plan for each.

Using this without over-reading it

• Budget by city and month. A lane through a station with 15 or more hot days in July loads the unit more than one with 2. Use your logs for gallons.
• Check the bill of lading for the temperature requirement. The weather count tells you how often the air is cold, not what your shipper requires.
• Do not price from normals alone. A 30-year average can hide a hot year. Use it to set a seasonal buffer, then review it against actual fuel receipts.
• Remember the station. It is an airport. Mountain passes, deserts and coasts on a route can differ a lot.
• Keep dated weather and fuel logs. They help in a claim or in a rate conversation.

Common questions

• What does "days at 90 F or more" mean? For each station and month, NOAA lists the average number of days when the highest air temperature reached 90 degrees Fahrenheit or more. A value of 16.4 for Atlanta in July means a typical July has about 16 such days.
• Is this a forecast? No. Normals are 30-year averages, so a single year can run well above or below. They tell you what is usual for the month, not what next week brings.
• Why one station per city? Each city uses the nearest airport-class station within 45 km of the city centre. Airport stations measure air temperature in a shaded screen, not pavement, trailer or cargo temperature.
• Where does the extra fuel number come from? From figures you type: run hours, extra gallons per hour and a price. We publish no reefer fuel rate.

The reefer heat and freeze days page has all 44 cities by month, a chart and the fuel calculator, so you can type your own run hours and gallons. And if your reefer loads pay less than they should for the fuel they burn, send us your last 20 loads.