# When will the next Category 5 hurricane form

> Before Dec 1, 2026 leads at 55%, runner-up 19% across 4 winner-take-all outcomes — refreshed 1 h ago.

URL: https://simplefunctions.dev/odds/nextcat5hurdate
Updated: 2026-08-24T13:20:51.962Z
Category: climate
Status: active
Closes: 2026-12-01

## Headline

- Leader: Before Dec 1, 2026 at 55%
- Runner-up: Before Nov 1, 2026 at 19%
- Outcomes: 4 (winner-take-all)
- Venue: Kalshi (4 contracts)
- 24h volume: $100

## Bound contracts (4)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| Before Dec 1, 2026 | 55¢ | +9pp | $0 | kalshi | /markets/when-will-the-next-category-5-hurricane-form-befor-kalshi-kxnextcat5hurdate-26dec01-26dec01 |
| Before Nov 1, 2026 | 19¢ | +1pp | $0 | kalshi | /markets/when-will-the-next-category-5-hurricane-form-befor-kalshi-kxnextcat5hurdate-26dec01-26nov01 |
| Before Oct 1, 2026 | 14¢ | +6pp | $100 | kalshi | /markets/when-will-the-next-category-5-hurricane-form-befor-kalshi-kxnextcat5hurdate-26dec01-26oct01 |
| Before Sep 1, 2026 | 3¢ | −3pp | $0 | kalshi | /markets/when-will-the-next-category-5-hurricane-form-befor-kalshi-kxnextcat5hurdate-26dec01-26sep01 |

## 30-day trajectory

| Day | Before Dec 1, 2026 | Before Nov 1, 2026 | Before Oct 1, 2026 |
|---|---|---|---|
| 2026-08-08 | 4 | 4 | 4 |
| 2026-08-10 | 5 | 6 | 6 |
| 2026-08-17 | 15 | 13 | 8 |
| 2026-08-23 | 33 | 16 | 10 |

_15 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-08-21 · Before Oct 1, 2026 −13pp 20→7¢ · kalshi
- 2026-08-20 · Before Oct 1, 2026 +10pp 10→20¢ · kalshi
- 2026-08-23 · Before Dec 1, 2026 +9pp 24→33¢ · kalshi
- 2026-08-17 · Before Nov 1, 2026 +7pp 6→13¢ · kalshi
- 2026-08-23 · Before Oct 1, 2026 +6pp 4→10¢ · kalshi

## Analysis

This probability measures the chance that a Category 5 hurricane will form before September 1, 2026—just three weeks away. Markets currently estimate this at 4%, reflecting the rarity of Category 5 storms and the advanced stage of the 2026 Atlantic hurricane season. The assessment depends on current sea surface temperatures, atmospheric conditions, and historical frequency: Category 5 hurricanes form in only a small fraction of Atlantic seasons. If tropical activity accelerates significantly in late August, or if satellite data shows unusual ocean warming patterns, this probability would likely rise. The main near-term catalyst is early September itself—if no Category 5 forms by September 1, the market will shift focus to the October 1 and November 1 contract windows, when hurricane season typically peaks. Real-time monitoring of developing tropical systems and sea surface temperature anomalies will be the primary drivers of probability movement.

### Key factors

- Only 3 weeks remain until the September 1 deadline, and no major tropical systems are currently forecast to rapidly intensify to Category 5 strength
- Historical data shows Category 5 hurricanes are rare events; fewer than 20 have formed in the Atlantic basin since 1850, with clustering in certain decades
- Current Atlantic sea surface temperatures and atmospheric indicators would need to shift substantially to support rapid intensification
- September 1 serves as the immediate resolution date; if it passes without a Category 5, market focus shifts to later-season windows when conditions typically favor stronger storms
- Operational hurricane forecasting models and real-time satellite imagery of tropical systems will provide the clearest signals for probability revision

## Methodology

Headline is the **leader's price**, not an arithmetic mean — averaging disjoint winner-take-all outcomes is meaningless. Per-outcome prices come from the venue's last-traded mid; cross-venue values are simple means across contracts on each venue.

## How to use this data

- HTML: https://simplefunctions.dev/odds/nextcat5hurdate
- JSON: https://simplefunctions.dev/api/public/odds?slug=nextcat5hurdate

## License

CC-BY-4.0. Attribute "SimpleFunctions" with a link to https://simplefunctions.dev. See https://simplefunctions.dev/legal for terms.