Cosmic radiation on flights from Chicago (ORD) to New York (LGA)
A flight from Chicago O'Hare International Airport to LaGuardia Airport at 35,000 ft, about 1 h 35 min in the air, receives about 0.00487 mSv (4.87 µSv) of cosmic radiation: about 5% 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
- 4.87 µSv0.00487 mSv
- Time in the air
- 1 h 35 minestimated
- Dose rate
- 3.1 µSv/haverage, 35,000 ft
- Chest X‑rays
- 0.049at 0.1 mSv each
Key facts: ORD → LGA
| Dose, standard flight | 0.00487 mSv (4.87 µSv) |
|---|---|
| Time in the air | 1 h 35 min, estimated from distance and prevailing winds |
| Cruise altitude | 35,000 ft |
| Average dose rate | 3.1 µSv/h |
| Great-circle distance | 1,177 km (731 mi) |
| Furthest from the equator | 42.0°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, 1 h 35 min in the air (climb 25 min, cruise 53 min, descent 17 min), effective dose per ICRP Publication 103. How it's calculated.
How the sun changes the dose on ORD → LGA
The sun's 11-year cycle moves this number. With the same 1 h 35 min at 35,000 ft, the flight would have received 0.00613 mSv in April 2020, when the sun was quiet and more galactic cosmic rays reached the atmosphere, and 0.00377 mSv in January 2026, near solar maximum: 63% more at the quiet end. In August 2026 it is 0.00487 mSv.
The numbers behind the chart
| Month | Dose | Dose |
|---|---|---|
| January 2016 | 5.38 µSv | 0.00538 mSv |
| April 2016 | 5.54 µSv | 0.00554 mSv |
| July 2016 | 5.52 µSv | 0.00552 mSv |
| October 2016 | 5.72 µSv | 0.00572 mSv |
| January 2017 | 5.79 µSv | 0.00579 mSv |
| April 2017 | 5.94 µSv | 0.00594 mSv |
| July 2017 | 5.82 µSv | 0.00582 mSv |
| October 2017 | 5.77 µSv | 0.00577 mSv |
| January 2018 | 5.87 µSv | 0.00587 mSv |
| April 2018 | 6.03 µSv | 0.00603 mSv |
| July 2018 | 6 µSv | 0.006 mSv |
| October 2018 | 6.13 µSv | 0.00613 mSv |
| January 2019 | 5.82 µSv | 0.00582 mSv |
| April 2019 | 6.11 µSv | 0.00611 mSv |
| July 2019 | 6.02 µSv | 0.00602 mSv |
| October 2019 | 6.11 µSv | 0.00611 mSv |
| January 2020 | 6.08 µSv | 0.00608 mSv |
| April 2020 | 6.13 µSv | 0.00613 mSv |
| July 2020 | 6.09 µSv | 0.00609 mSv |
| October 2020 | 6.09 µSv | 0.00609 mSv |
| January 2021 | 5.88 µSv | 0.00588 mSv |
| April 2021 | 6.11 µSv | 0.00611 mSv |
| July 2021 | 5.96 µSv | 0.00596 mSv |
| October 2021 | 5.99 µSv | 0.00599 mSv |
| January 2022 | 5.86 µSv | 0.00586 mSv |
| April 2022 | 5.79 µSv | 0.00579 mSv |
| July 2022 | 5.29 µSv | 0.00529 mSv |
| October 2022 | 5.47 µSv | 0.00547 mSv |
| January 2023 | 4.97 µSv | 0.00497 mSv |
| April 2023 | 5.03 µSv | 0.00503 mSv |
| July 2023 | 4.72 µSv | 0.00472 mSv |
| October 2023 | 4.75 µSv | 0.00475 mSv |
| January 2024 | 4.46 µSv | 0.00446 mSv |
| April 2024 | 4.6 µSv | 0.0046 mSv |
| July 2024 | 4.64 µSv | 0.00464 mSv |
| October 2024 | 4.01 µSv | 0.00401 mSv |
| January 2025 | 4.16 µSv | 0.00416 mSv |
| April 2025 | 4.17 µSv | 0.00417 mSv |
| July 2025 | 4.12 µSv | 0.00412 mSv |
| October 2025 | 4.24 µSv | 0.00424 mSv |
| January 2026 | 3.77 µSv | 0.00377 mSv |
| April 2026 | 4.31 µSv | 0.00431 mSv |
| July 2026 | 4.64 µSv | 0.00464 mSv |
| August 2026 | 4.87 µSv | 0.00487 mSv |
How cruise altitude changes the dose
Flown at 31,000 ft instead, the same flight would receive 0.00352 mSv, 28% less than at 35,000 ft; at 41,000 ft it would receive 0.00714 mSv, 47% 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 ORD → LGA, with the same 1 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)
| 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 | 3.88 | 4.16 | 4.22 | 4.18 | 4.36 | 4.22 | 4.21 | 3.59 | 3.23 | 3.02 | 2.75 | 3.52 |
| 33,000 ft | 4.6 | 4.94 | 5.01 | 4.97 | 5.18 | 5.02 | 5 | 4.25 | 3.82 | 3.58 | 3.24 | 4.17 |
| 35,000 ft | 5.38 | 5.79 | 5.87 | 5.82 | 6.08 | 5.88 | 5.86 | 4.97 | 4.46 | 4.16 | 3.77 | 4.87 |
| 37,000 ft | 6.2 | 6.68 | 6.78 | 6.72 | 7.02 | 6.79 | 6.76 | 5.72 | 5.12 | 4.78 | 4.32 | 5.6 |
| 39,000 ft | 7.06 | 7.61 | 7.73 | 7.66 | 8.01 | 7.73 | 7.71 | 6.49 | 5.81 | 5.41 | 4.88 | 6.36 |
| 41,000 ft | 7.94 | 8.57 | 8.71 | 8.63 | 9.03 | 8.72 | 8.69 | 7.29 | 6.51 | 6.05 | 5.44 | 7.14 |
The return flight: LGA → ORD
LGA → ORD receives 0.00593 mSv at 35,000 ft, 22% more than ORD → LGA, over about 1 h 49 min in the air against 1 h 35 min. The return takes 14 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.
What 4.87 µSv compares with
| Compared with | Its dose | This flight is |
|---|---|---|
| Chest X-Ray | 0.1 mSv | about 5% of a chest X-ray |
| Dental X-Ray | 0.005 mSv | about a dental X-ray |
| Background Radiation (Daily) | 0.008 mSv | about two thirds of a day's natural background radiation |
| Mammogram | 0.4 mSv | about 1% of a mammogram |
| Head CT Scan | 2 mSv | about 1% of a head CT scan |
| Eating a Banana | 0.0001 mSv | about 49 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 0.00352 mSv, 28% less than at 35,000 ft; at 41,000 ft it would receive 0.00714 mSv, 47% 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 1.5 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 63% 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.