Climate

Humboldt Current, a cold Pacific Ocean current that flows north from Antarctica to the western coast of South America (also cause of El Nino)

The Humboldt Current keeps the climate mild and dry, temps rarely above 80F

DRY SEASON: From May to Dec. (winter in Southern Hemisphere) winds blow from SE, cooling the islands with colder water. Higher up, clouds of moisture (mist) supports vegitation, shorelands are dry, so cacti and lichen are prevalent.

WET SEASON: Jan. to April (summer in Southern Hemisphere) winds decrease. sea is warmer; calm sea, warm days. Heavy rain in upper elevation in mountains, sends streams to lowlands and shoreline.

EL NINO: Humboldt current gone, so dry season never arrives. warm seas bring heavy rainfall. El Nino kills populations, destroys ground due to flooding. Warm seas have altered food chain. kills even algea.

Climate is unique in Galapagos due to uniqueness of islands (position, etc.)

photo courtesy of Bob Kusik

average rain and weather cond.

jan. 68mm 77F 25C

feb. 91mm 78F 26C

march 94mm 83F 28C

april 72mm 83F 28C

may 34mm 77F 25C

june 23mm 72F 23C

july 14mm 75F 22C

sept. 06mm 70F 22C

oct. 06mm 71F 21C

nov. 07mm 73F 22C

dec. 30mm 74F 23C

dec.-may. cloudier and tropical. ocean temps higher.

jun.-dec. mid-day showers/ misty. ocean temp lower.

DRY SEASON-garua - provides more moisture due to misty highlands. ocean temp. 68F

Considering that these islands are placed directly under the equator, the climate is far from being excessively hot; this seems chiefly caused by the singularly low temperature of the surrounding water, brought here by the great southern Polar current. Excepting during one short season, very little rain falls, and even then it is irregular; but the clouds generally hang low.

--Charles Darwin

In addition to humboldt current, also cromwell current (south equatorial countercurrent)

cromwell current is nutrient rich and approaches from western shores. western waters fo galapagos are colder and richer in marine life.

more infor on El Nino found in summary.