Cosmic radiation on flights from New York (JFK) to Hong Kong (HKG)
A flight from John F. Kennedy International Airport to Hong Kong International Airport at 35,000 ft, about 15 h 24 min in the air, receives about 0.0611 mSv (61.1 µSv) of cosmic radiation: about two thirds 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
- 61.1 µSv0.0611 mSv
- Time in the air
- 15 h 24 minestimated
- Dose rate
- 4.0 µSv/haverage, 35,000 ft
- Chest X‑rays
- 0.61at 0.1 mSv each
Key facts: JFK → HKG
| Dose, standard flight | 0.0611 mSv (61.1 µSv) |
|---|---|
| Time in the air | 15 h 24 min, estimated from distance and prevailing winds |
| Cruise altitude | 35,000 ft |
| Average dose rate | 4.0 µSv/h |
| Great-circle distance | 12,966 km (8,057 mi) |
| Furthest from the equator | 83.7°N |
| Solar conditions | August 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, 15 h 24 min in the air (climb 25 min, cruise 882 min, descent 17 min), effective dose per ICRP Publication 103. How it's calculated.
How the sun changes the dose on JFK → HKG
The sun's 11-year cycle moves this number. With the same 15 h 24 min at 35,000 ft, the flight would have received 0.0778 mSv in April 2020, when the sun was quiet and more galactic cosmic rays reached the atmosphere, and 0.0476 mSv in January 2026, near solar maximum: 64% more at the quiet end. In August 2026 it is 0.0611 mSv.
The numbers behind the chart
| Month | Dose | Dose |
|---|---|---|
| January 2016 | 67.8 µSv | 0.0678 mSv |
| April 2016 | 69.8 µSv | 0.0698 mSv |
| July 2016 | 69.5 µSv | 0.0695 mSv |
| October 2016 | 72.1 µSv | 0.0721 mSv |
| January 2017 | 73.1 µSv | 0.0731 mSv |
| April 2017 | 75.1 µSv | 0.0751 mSv |
| July 2017 | 73.6 µSv | 0.0736 mSv |
| October 2017 | 72.8 µSv | 0.0728 mSv |
| January 2018 | 74.3 µSv | 0.0742 mSv |
| April 2018 | 76.4 µSv | 0.0764 mSv |
| July 2018 | 76 µSv | 0.076 mSv |
| October 2018 | 77.7 µSv | 0.0777 mSv |
| January 2019 | 73.6 µSv | 0.0736 mSv |
| April 2019 | 77.5 µSv | 0.0775 mSv |
| July 2019 | 76.3 µSv | 0.0763 mSv |
| October 2019 | 77.5 µSv | 0.0775 mSv |
| January 2020 | 77 µSv | 0.077 mSv |
| April 2020 | 77.8 µSv | 0.0778 mSv |
| July 2020 | 77.2 µSv | 0.0772 mSv |
| October 2020 | 77.2 µSv | 0.0772 mSv |
| January 2021 | 74.3 µSv | 0.0743 mSv |
| April 2021 | 77.5 µSv | 0.0775 mSv |
| July 2021 | 75.5 µSv | 0.0755 mSv |
| October 2021 | 75.8 µSv | 0.0758 mSv |
| January 2022 | 74 µSv | 0.074 mSv |
| April 2022 | 73.2 µSv | 0.0732 mSv |
| July 2022 | 66.6 µSv | 0.0666 mSv |
| October 2022 | 68.9 µSv | 0.0689 mSv |
| January 2023 | 62.4 µSv | 0.0624 mSv |
| April 2023 | 63.2 µSv | 0.0632 mSv |
| July 2023 | 59.3 µSv | 0.0593 mSv |
| October 2023 | 59.6 µSv | 0.0596 mSv |
| January 2024 | 56 µSv | 0.056 mSv |
| April 2024 | 57.7 µSv | 0.0577 mSv |
| July 2024 | 58.3 µSv | 0.0583 mSv |
| October 2024 | 50.5 µSv | 0.0505 mSv |
| January 2025 | 52.4 µSv | 0.0524 mSv |
| April 2025 | 52.4 µSv | 0.0524 mSv |
| July 2025 | 51.9 µSv | 0.0519 mSv |
| October 2025 | 53.3 µSv | 0.0533 mSv |
| January 2026 | 47.6 µSv | 0.0476 mSv |
| April 2026 | 54.2 µSv | 0.0542 mSv |
| July 2026 | 58.3 µSv | 0.0583 mSv |
| August 2026 | 61.1 µSv | 0.0611 mSv |
How cruise altitude changes the dose
Flown at 31,000 ft instead, the same flight would receive 0.0443 mSv, 28% less than at 35,000 ft; at 41,000 ft it would receive 0.0889 mSv, 45% more. Same route, same time in the air, same month: only the air overhead changes.
Try it: change the altitude and the month
Every combination is its own CARI-7 run for JFK → HKG, with the same 15 h 24 min in the air. It is still a standard flight, not yours: the app calculates your exact flight.
Every combination as a table (µSv)
| Altitude | Jan 2016 | Jan 2017 | Jan 2018 | Jan 2019 | Jan 2020 | Jan 2021 | Jan 2022 | Jan 2023 | Jan 2024 | Jan 2025 | Jan 2026 | Aug 2026 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 31,000 ft | 48.8 | 52.5 | 53.3 | 52.8 | 55.2 | 53.3 | 53.2 | 45.1 | 40.7 | 38.2 | 34.8 | 44.3 |
| 33,000 ft | 58 | 62.4 | 63.4 | 62.9 | 65.7 | 63.5 | 63.2 | 53.5 | 48.1 | 45.1 | 41 | 52.4 |
| 35,000 ft | 67.8 | 73.1 | 74.3 | 73.6 | 77 | 74.3 | 74 | 62.4 | 56 | 52.4 | 47.6 | 61.1 |
| 37,000 ft | 78 | 84.2 | 85.6 | 84.8 | 88.9 | 85.7 | 85.4 | 71.7 | 64.2 | 59.9 | 54.3 | 70.2 |
| 39,000 ft | 88.5 | 95.8 | 97.4 | 96.5 | 101 | 97.5 | 97.1 | 81.2 | 72.5 | 67.6 | 61.1 | 79.5 |
| 41,000 ft | 99.3 | 108 | 110 | 109 | 114 | 110 | 109 | 90.8 | 80.9 | 75.2 | 67.8 | 88.9 |
The return flight: HKG → JFK
HKG → JFK receives 0.0601 mSv at 35,000 ft, 2% less than JFK → HKG, over about 15 h 6 min in the air against 15 h 24 min. The return is 18 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.
What 61.1 µSv compares with
| Compared with | Its dose | This flight is |
|---|---|---|
| Chest X-Ray | 0.1 mSv | about two thirds of a chest X-ray |
| Dental X-Ray | 0.005 mSv | about 12 dental X-rays |
| Background Radiation (Daily) | 0.008 mSv | about 7.6 days of natural background radiation |
| Mammogram | 0.4 mSv | about 15% of a mammogram |
| Head CT Scan | 2 mSv | about 3% of a head CT scan |
| Eating a Banana | 0.0001 mSv | about 611 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 0.0443 mSv, 28% less than at 35,000 ft; at 41,000 ft it would receive 0.0889 mSv, 45% 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 2 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 64% 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.