The folks at spaceweather.com have begun publishing a regular table of "hot flights" that lists the five charter and commercial flights within the continental US with highest dose rates of so-called "aviation radiation" for each day.
The lists come from a model called E-RAD (for Empirical Radiation) based on GPS-tagged radiation measurements from 1,400 flights criss-crossing the country every day.
"We are constantly flying radiation sensors onboard airplanes over the US and around the world, so far collecting more than 18,000 GPS-tagged radiation measurements," explains an introduction on the site. "Using this unique dataset, we can predict the dosage on any flight over the USA with an error no worse than 15%."
Of course, there is radiation all around us, primarily coming from our sun. Our planet's atmosphere and magnetic field block a lot of these cell-damaging rays, so the higher you fly, the less natural atmospheric protection there is.
This is especially bad news for charter flights that tend to fly at higher elevations than scheduled commercial flights.
According to the E-RAD data, XOJET flight 760 from Santa Ana, California to Teterboro Airport in New Jersey comes with a radiation dose 81.1 times what you would be battered with if you stayed at sea level and made a road trip out of it. This is thanks in part to the fact that the cruising altitude for the flight is at 47,000 feet, over a mile higher than most commercial flights.
That's just one example. The rankings change daily based on flight schedules for a given day.
The five commercial flights that current data lists as the most radioactive fly around a mile lower than the above charter and around a mile higher than commercial flights with average radiation doses (which is still about 39 times more than you get on the ground).
On Tuesday, a pair of United flights from Santa Ana to Newark came with over 60 times what you get zapped with at the beach.
I reached out to a handful of airlines and the trade group Airlines for America for their thoughts. So far none have offered a comment for this story. Airlines for America referred me to the Federal Aviation Administration and this circular with some basic background on in-flight ionizing (potentially damaging) radiation.
As for the lowest doses of radiation, you'll want to stick to short, lower altitude flights. In fact, the five lowest dose flights on the table on Tuesday (which are still between 16.1 and 19.2 times sea level dosing) were all Compass Airlines flights from Los Angeles to San Jose.
But for such a short trip, it might really be more practical to just drive those few hours and skip being irradiated in the air altogether.