1989 Western Pacific typhoon season
Typhoon Irma 1989
Typhoon Irma spent much of its early life as a weak circulation before intensifying sharply over the Philippine Sea in late November 1989. Its course then curved away from the Philippines, keeping the center offshore.
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161 mph
Nov 30, 1989 during the tropical stage
Full archive record, including non-tropical stages if present
Along the recorded center positions
STORM HISTORY
A long weak phase across the Pacific
Irma's archived track begins north of the Marshall Islands on 20 November. It moved west and then southwest for several days, remaining weak. The route carried it south of Guam before it turned west-northwest into the Philippine Sea.
Strengthening accelerated over warmer water. Irma reached Category 5 intensity after a rapid final increase in winds, with the archive recording a peak of 140 kt early on 30 November.
Turning away from the Philippines
Irma weakened as it approached the waters east of Luzon, then turned north and northeast. Its winds declined steadily during this turn, and the circulation moved back toward the open Pacific.
The archived track ends on 5 December with no center position over land. Irma's short period of extreme intensity came near the end of a much longer oceanic journey.
Further reading
QUICK ANSWERS
Irma in brief
What was Typhoon Irma's highest wind speed?
161 mph, the highest one-minute sustained wind in its tropical stage, recorded on Nov 30, 1989, 12:00 AM UTC.
What category was Typhoon Irma?
Category 5 at its peak on the Saffir–Simpson one-minute wind scale, first reaching Category 5 on Nov 30, 1989, 12:00 AM UTC. Other agencies classify storms differently.
What was Typhoon Irma's lowest pressure?
925 mb, the minimum central pressure recorded during its tropical stage, on Nov 30, 1989, 12:00 AM UTC.
When did Typhoon Irma occur?
The archived track runs from Nov 20, 1989, 12:00 AM UTC to Dec 5, 1989, 12:00 PM UTC, with the tropical stage from Nov 20, 1989, 12:00 AM UTC to Dec 5, 1989, 12:00 PM UTC.
Where did Typhoon Irma form?
In the Western Pacific basin, in the 1989 season. Its first archived position is 17.2°N, 173.9°E on Nov 20, 1989, 12:00 AM UTC.
Did Typhoon Irma make landfall?
No archived position places Typhoon Irma's center over land, but positions are six-hourly and a brief landfall can fall between them.
METHODOLOGY
Data sources and limitations
The map and summary are generated from NOAA's IBTrACS v04r01 archive. Wind and category use US-agency records; minimum pressure is calculated during the tropical stage, with the archive's pressure source retained. Category 5 refers to the Saffir–Simpson one-minute wind scale; local agencies may use different classifications. Coastlines use Natural Earth's 1:10m land data.
Track distance adds great-circle distances between consecutive observations, excluding gaps over 12 hours. This track has no gaps over 12 hours. The line shows the storm's center, not its size, rainfall or flood extent. Converted wind speeds are rounded to the nearest whole unit.
Archive retrieved
NOAA IBTrACS archive and Field documentation
Sources & methodology