Climate considerations for Green Building
San Miguel de Allende enjoys a pleasant Tropical Highland climate with distinct wet and dry seasons. Because of our low latitude (20° N), days and nights are of almost equal length and seasonal variations in temperature are small. Our high altitude (6000 ft/1900 m) causes rapid warming during the day and rapid cooling at night so that the temperature variation during a single day can be quite large. Annual rainfall of over 20 inches (50 cm) is normal, most of it falling during the summer months.
Weather history and current weather conditions are available at San Miguel de Allende Weather.
Rainfall (inches)
| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | year | |
| 2009 | 0.1 | 0.0 | 0.2 | 0.1 | 0.9 | 3.2 | 3.9 | 2.8 | 1.8 | 2.0 | 15.0 | ||
| 2008 | 0.0 | 0.2 | 0.0 | 0.2 | 1.4 | 2.6 | 7.6 | 7.5 | 2.1 | 0.1 | 0.0 | 0.0 | 21.8 |
| 2007 | 0.4 | 1.9 | 0.1 | 0.1 | 1.0 | 5.3 | 6.2 | 2.0 | 2.6 | 0.2 | 1.0 | 0.4 | 21.3 |
| 2006 | 5.8 | 5.2 | 4.6 | 4.5 | 0.7 | 0.4 | >21.5 |
San Miguel's aquifer is in danger of depletion. Responsible building should include rainwater harvesting and water-friendly landscaping.
Solar Radiation (kilowatt-hours per square meter per day)
| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | year | |
| 2009 average | 5.0 | 6.1 | 6.7 | 7.3 | 6.8 | 6.4 | 6.7 | 6.2 | 5.1 | 4.8 | |||
| highest day | 5.9 | 6.8 | 7.7 | 8.0 | 8.1 | 8.0 | 8.1 | 7.8 | 7.0 | 6.7 | |||
| lowest day | 1.3 | 4.6 | 4.7 | 5.6 | 4.9 | 2.3 | 3.0 | 2.5 | 3.0 | 2.4 | |||
| lowest 3-day | 2.5 | 5.5 | 5.2 | 6.0 | 5.3 | 4.4 | 4.0 | 3.2 | 3.6 | 3.3 | |||
| lowest 5-day | 3.2 | 5.7 | 5.7 | 6.5 | 5.5 | 4.8 | 5.1 | 4.2 | 3.6 | 3.6 | |||
| lowest 7-day | 3.7 | 5.7 | 5.9 | 6.8 | 5.7 | 4.9 | 5.8 | 4.9 | 3.8 | 3.8 |
San Miguel de Allende is an ideal location for solar power systems. Many homes are already using solar panels to provide all or part of their electricity. 'Lowest x-day' measurements are the lowest average kilowatt hours per day received during several consecutive days. This information is useful for sizing battery capacity to provide energy during cloudy periods.
Heating Degree Days (base 65F)
| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | year | |
| 2009 | 349 | 268 | 201 | 105 | 79 | 73 | 90 | 95 | 83 | 148 | |||
| 2008 | 376 | 235 | 205 | 109 | 79 | 87 | 110 | 99 | 138 | 237 | 325 | 392 | 2390 |
| 2007 | 347 | 252 | 201 | 117 | 84 | 82 | 93 | 109 | 138 | 243 | 309 | 296 | 2270 |
| 2006 | 92 | 94 | 102 | 164 | 302 | 380 | ------ |
Cooling Degree Days (base 65F)
| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | year | |
| 2009 | 63 | 95 | 146 | 214 | 223 | 188 | 155 | 149 | 89 | 103 | |||
| 2008 | 55 | 101 | 137 | 221 | 222 | 146 | 84 | 96 | 59 | 68 | 55 | 55 | 1299 |
| 2007 | 42 | 72 | 135 | 179 | 210 | 149 | 110 | 96 | 88 | 91 | 63 | 74 | 1307 |
| 2006 | 113 | 87 | 85 | 79 | 53 | 35 | ------ |
Unlike most locations, San Miguel experiences both warm and cool weather within a single day. Passive heating and cooling designs can exploit this to create comfortable dwellings that are energy efficient.