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

Reverse: New York → Los Angeles

A flight from Los Angeles International Airport to John F. Kennedy International Airport at 35,000 ft, about 4 h 35 min in the air, receives about 0.0172 mSv (17.2 µSv) of cosmic radiation: about 17% 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
17.2 µSv0.0172 mSv
Time in the air
4 h 35 minestimated
Dose rate
3.7 µSv/haverage, 35,000 ft
Chest X‑rays
0.17at 0.1 mSv each

Key facts: LAX → JFK

Dose, standard flight0.0172 mSv (17.2 µSv)
Time in the air4 h 35 min, estimated from distance and prevailing winds
Cruise altitude35,000 ft
Average dose rate3.7 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, 4 h 35 min in the air (climb 25 min, cruise 233 min, descent 17 min), effective dose per ICRP Publication 103. How it's calculated.

LAXJFK
Great-circle route, shaded from 3.0 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 LAX → JFK

The sun's 11-year cycle moves this number. With the same 4 h 35 min at 35,000 ft, the flight would have received 0.021 mSv in April 2020, when the sun was quiet and more galactic cosmic rays reached the atmosphere, and 0.0136 mSv in January 2026, near solar maximum: 54% more at the quiet end. In August 2026 it is 0.0172 mSv.

Dose for this flight at 35,000 ft, quarterly
0 µSv10 µSv20 µSv30 µSv20162018202020222024202621 µSv13.6 µSv17.2 µSv
0 µSv10 µSv20 µSv30 µSv20162020202421 µSv13.6 µSv17.2 µSv
The numbers behind the chart
MonthDoseDose
January 201618.8 µSv0.0188 mSv
April 201619.3 µSv0.0193 mSv
July 201619.2 µSv0.0192 mSv
October 201619.8 µSv0.0198 mSv
January 201720 µSv0.02 mSv
April 201720.4 µSv0.0204 mSv
July 201720.1 µSv0.0201 mSv
October 201719.9 µSv0.0199 mSv
January 201820.3 µSv0.0203 mSv
April 201820.7 µSv0.0207 mSv
July 201820.6 µSv0.0206 mSv
October 201821 µSv0.021 mSv
January 201920.1 µSv0.0201 mSv
April 201921 µSv0.021 mSv
July 201920.7 µSv0.0207 mSv
October 201921 µSv0.021 mSv
January 202020.9 µSv0.0209 mSv
April 202021 µSv0.021 mSv
July 202020.9 µSv0.0209 mSv
October 202020.9 µSv0.0209 mSv
January 202120.3 µSv0.0203 mSv
April 202121 µSv0.021 mSv
July 202120.5 µSv0.0205 mSv
October 202120.6 µSv0.0206 mSv
January 202220.2 µSv0.0202 mSv
April 202220 µSv0.02 mSv
July 202218.5 µSv0.0185 mSv
October 202219 µSv0.019 mSv
January 202317.5 µSv0.0175 mSv
April 202317.7 µSv0.0177 mSv
July 202316.7 µSv0.0167 mSv
October 202316.8 µSv0.0168 mSv
January 202415.9 µSv0.0159 mSv
April 202416.3 µSv0.0163 mSv
July 202416.4 µSv0.0164 mSv
October 202414.4 µSv0.0144 mSv
January 202514.9 µSv0.0149 mSv
April 202514.9 µSv0.0149 mSv
July 202514.8 µSv0.0148 mSv
October 202515.2 µSv0.0152 mSv
January 202613.6 µSv0.0136 mSv
April 202615.4 µSv0.0154 mSv
July 202616.4 µSv0.0164 mSv
August 202617.2 µSv0.0172 mSv

How cruise altitude changes the dose

Flown at 31,000 ft instead, the same flight would receive 0.0125 mSv, 27% less than at 35,000 ft; at 41,000 ft it would receive 0.0248 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 ft12.5 µSv
  • 33,000 ft14.8 µSv
  • 35,000 ft17.2 µSv
  • 37,000 ft19.7 µSv
  • 39,000 ft22.2 µSv
  • 41,000 ft24.8 µSv

Try it: change the altitude and the month

Every combination is its own CARI-7 run for LAX → JFK, with the same 4 h 35 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 ft13.614.514.714.615.114.714.612.711.610.99.9812.5
33,000 ft16.117.117.417.217.917.417.31513.712.811.814.8
35,000 ft18.82020.320.120.920.320.217.515.914.913.617.2
37,000 ft21.52323.323.12423.323.22018.217.115.519.7
39,000 ft24.42626.426.227.226.426.322.620.519.217.522.2
41,000 ft27.229.129.529.330.429.529.425.322.821.419.424.8

The return flight: JFK → LAX

JFK → LAX receives 0.0202 mSv at 35,000 ft, 18% more than LAX → JFK, over about 5 h 19 min in the air against 4 h 35 min. The return takes 44 min longer: its track runs against 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
  • LAX → JFK17.2 µSv
  • JFK → LAX20.2 µSv

Cosmic radiation on New York → Los Angeles flights

What 17.2 µSv compares with

Compared withIts doseThis flight is
Chest X-Ray0.1 mSvabout 17% of a chest X-ray
Dental X-Ray0.005 mSvabout 3.4 dental X-rays
Background Radiation (Daily)0.008 mSvabout 2.1 days of natural background radiation
Mammogram0.4 mSvabout 4% of a mammogram
Head CT Scan2 mSvabout 1% of a head CT scan
Eating a Banana0.0001 mSvabout 172 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 0.0125 mSv, 27% less than at 35,000 ft; at 41,000 ft it would receive 0.0248 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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