20 knots of wind means that the wind is blowing at a speed of 20 nautical miles per hour.

Here's a breakdown:

* Knots are a unit of speed used primarily in nautical contexts.

* Nautical miles are slightly longer than statute miles (1 nautical mile = 1.15 statute miles).

So, 20 knots is equivalent to about 23 statute miles per hour.

Here's a general guide to wind speed in knots:

* 0-3 knots: Calm

* 4-6 knots: Light air

* 7-10 knots: Light breeze

* 11-16 knots: Gentle breeze

* 17-21 knots: Moderate breeze

* 22-27 knots: Fresh breeze

* 28-33 knots: Strong breeze

* 34-40 knots: Moderate gale

* 41-47 knots: Fresh gale

* 48-55 knots: Strong gale

* 56-63 knots: Storm

* 64 knots and above: Hurricane

Note: These are just general guidelines, and the actual impact of wind depends on many factors, including the location, terrain, and the object being affected by the wind.