Cosmic radiation on flights from New York (JFK) to Los Angeles (LAX)

Reverse: Los Angeles → New York

A flight from John F. Kennedy International Airport to Los Angeles International Airport at 35,000 ft, about 5 h 19 min in the air, receives about 0.0202 mSv (20.2 µSv) of cosmic radiation: about a fifth of a chest X-ray. That is the FAA's CARI-7 model run for this route with the solar conditions of August 2026.

Updated · solar conditions of August 2026

Dose
20.2 µSv0.0202 mSv
Time in the air
5 h 19 minestimated
Dose rate
3.8 µSv/haverage, 35,000 ft
Chest X‑rays
0.2at 0.1 mSv each

Key facts: JFK → LAX

Dose, standard flight0.0202 mSv (20.2 µSv)
Time in the air5 h 19 min, estimated from distance and prevailing winds
Cruise altitude35,000 ft
Average dose rate3.8 µSv/h
Great-circle distance3,974 km (2,469 mi)
Furthest from the equator40.8°N
Solar conditionsAugust 2026

The standard flight is CARI-7, the FAA Civil Aerospace Medical Institute's model, run on the dev machine for this route: 35,000 ft, 5 h 19 min in the air (climb 25 min, cruise 277 min, descent 17 min), effective dose per ICRP Publication 103. How it's calculated.

JFKLAX
Great-circle route, shaded from 3.1 µSv/h to 4.1 µSv/h. Shading is modelled from the monthly dose-rate grid; totals are CARI-7.

How the sun changes the dose on JFK → LAX

The sun's 11-year cycle moves this number. With the same 5 h 19 min at 35,000 ft, the flight would have received 0.0247 mSv in April 2020, when the sun was quiet and more galactic cosmic rays reached the atmosphere, and 0.016 mSv in January 2026, near solar maximum: 54% more at the quiet end. In August 2026 it is 0.0202 mSv.

Dose for this flight at 35,000 ft, quarterly
0 µSv10 µSv20 µSv30 µSv20162018202020222024202624.7 µSv16 µSv20.2 µSv
0 µSv10 µSv20 µSv30 µSv20162020202424.7 µSv16 µSv20.2 µSv
The numbers behind the chart
MonthDoseDose
January 201622.1 µSv0.0221 mSv
April 201622.6 µSv0.0226 mSv
July 201622.5 µSv0.0225 mSv
October 201623.2 µSv0.0232 mSv
January 201723.5 µSv0.0235 mSv
April 201724 µSv0.024 mSv
July 201723.6 µSv0.0236 mSv
October 201723.4 µSv0.0234 mSv
January 201823.8 µSv0.0238 mSv
April 201824.3 µSv0.0243 mSv
July 201824.2 µSv0.0242 mSv
October 201824.7 µSv0.0247 mSv
January 201923.6 µSv0.0236 mSv
April 201924.6 µSv0.0246 mSv
July 201924.3 µSv0.0243 mSv
October 201924.6 µSv0.0246 mSv
January 202024.5 µSv0.0245 mSv
April 202024.7 µSv0.0247 mSv
July 202024.5 µSv0.0245 mSv
October 202024.5 µSv0.0245 mSv
January 202123.8 µSv0.0238 mSv
April 202124.6 µSv0.0246 mSv
July 202124.1 µSv0.0241 mSv
October 202124.2 µSv0.0242 mSv
January 202223.7 µSv0.0237 mSv
April 202223.5 µSv0.0235 mSv
July 202221.7 µSv0.0217 mSv
October 202222.3 µSv0.0223 mSv
January 202320.5 µSv0.0205 mSv
April 202320.8 µSv0.0208 mSv
July 202319.6 µSv0.0196 mSv
October 202319.7 µSv0.0197 mSv
January 202418.7 µSv0.0187 mSv
April 202419.2 µSv0.0192 mSv
July 202419.3 µSv0.0193 mSv
October 202416.9 µSv0.0169 mSv
January 202517.5 µSv0.0175 mSv
April 202517.6 µSv0.0176 mSv
July 202517.4 µSv0.0174 mSv
October 202517.8 µSv0.0178 mSv
January 202616 µSv0.016 mSv
April 202618.1 µSv0.0181 mSv
July 202619.3 µSv0.0193 mSv
August 202620.2 µSv0.0202 mSv

How cruise altitude changes the dose

Flown at 31,000 ft instead, the same flight would receive 0.0147 mSv, 27% less than at 35,000 ft; at 41,000 ft it would receive 0.0291 mSv, 44% more. Same route, same time in the air, same month: only the air overhead changes.

Dose for this flight by cruise altitude, August 2026
  • 31,000 ft14.7 µSv
  • 33,000 ft17.4 µSv
  • 35,000 ft20.2 µSv
  • 37,000 ft23.1 µSv
  • 39,000 ft26.1 µSv
  • 41,000 ft29.1 µSv

Try it: change the altitude and the month

Every combination is its own CARI-7 run for JFK → LAX, with the same 5 h 19 min in the air. It is still a standard flight, not yours: the app calculates your exact flight.

Every combination as a table (µSv)
AltitudeJan 2016Jan 2017Jan 2018Jan 2019Jan 2020Jan 2021Jan 2022Jan 2023Jan 2024Jan 2025Jan 2026Aug 2026
31,000 ft161717.217.117.717.217.214.913.612.811.714.7
33,000 ft18.920.120.420.32120.420.417.716.115.113.817.4
35,000 ft22.123.523.823.624.523.823.720.518.717.51620.2
37,000 ft25.32727.327.128.127.327.323.521.42018.323.1
39,000 ft28.630.530.930.731.93130.926.624.122.620.626.1
41,000 ft3234.134.634.435.734.634.529.626.825.122.829.1

The return flight: LAX → JFK

LAX → JFK receives 0.0172 mSv at 35,000 ft, 15% less than JFK → LAX, over about 4 h 35 min in the air against 5 h 19 min. The return is 44 min shorter: its track runs with the prevailing westerly winds at cruise altitude. Cosmic radiation builds up with every minute aloft, so the longer direction collects more of it along the same path.

Dose for each direction, standard flight
  • JFK → LAX20.2 µSv
  • LAX → JFK17.2 µSv

Cosmic radiation on Los Angeles → New York flights

What 20.2 µSv compares with

Compared withIts doseThis flight is
Chest X-Ray0.1 mSvabout a fifth of a chest X-ray
Dental X-Ray0.005 mSvabout 4 dental X-rays
Background Radiation (Daily)0.008 mSvabout 2.5 days of natural background radiation
Mammogram0.4 mSvabout 5% of a mammogram
Head CT Scan2 mSvabout 1% of a head CT scan
Eating a Banana0.0001 mSvabout 202 bananas

The comparison values are the ones the FlightDose app uses.

Why your flight will differ

  • Altitude. Flown at 31,000 ft instead, the same flight would receive 0.0147 mSv, 27% less than at 35,000 ft; at 41,000 ft it would receive 0.0291 mSv, 44% more. Same route, same time in the air, same month: only the air overhead changes.
  • Time in the air. Every extra 30 minutes on this route adds about 1.9 µSv. Headwinds, holding and routing change it by tens of minutes on a long flight.
  • The month. The sun's 11-year cycle swings this route's dose by about 54% between quiet and active years.
  • The track. Airlines fly tracks that bend with the jet stream, not the exact great circle; a track further from the equator collects more.
  • Solar storms. A rare solar radiation storm can add to the dose for hours; CARI-7's monthly figures don't include one.

FlightDose calculates your exact flight.

Your date, your altitude, your time in the air, with live space weather, and a running total against the limits that matter to you.

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