September weather forecastMaunabo, PR
September
Weather in September
As September sets in, they start to see the initial signs of the transition of seasons in Maunabo. Observing a steady pattern of weather conditions, Maunabo remains a captivating city for visitors. Conditions in Maunabo slightly improve with the average wind speed reducing to 7.1mph (11.4km/h) from August’s 9.1mph (14.6km/h). September also witnesses a slight decrease in rainfall, improving overall climate stability. Despite these minor alterations in the climate, the city continues to be a welcome destination owing to its tropical weather.Temperature
September registers an average high-temperature of a still warm 84.6°F (29.2°C), slightly varied from August's 84.7°F (29.3°C). Maunabo welcomes an average low temperature of 78.1°F (25.6°C) in September, a gentle shift from the day's high.Heat index
For most parts of September, the heat index is computed to be a very hot 95°F (35°C). Incorporate special precautions, risk of heat exhaustion and heat cramps is substantial. Sustained activity could cause heatstroke.It is emphasized that the heat index's values are meant for shaded zones with mild winds. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', provides an understanding of perceived warmth by combining temperature and relative humidity. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. One should be aware that direct sunshine can amplify the perceived temperature, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
Perspiration and the resultant sweat evaporation are the body's natural thermostat, helping regulate temperature. An upsurge in relative humidity affects normal body cooling mechanisms by slowing evaporation, hence reducing the rate at which the body cools and intensifying the perception of heat. Overheating dangers loom when the body's heat release mechanisms are overshadowed by excessive gain.
Humidity
In September, the average relative humidity in Maunabo is 80%.Rainfall
In Maunabo, in September, it is raining for 20.4 days, with typically 3.62" (92mm) of accumulated precipitation. In Maunabo, during the entire year, the rain falls for 223.2 days and collects up to 27.87" (708mm) of precipitation.Daylight
In Maunabo, the average length of the day in September is 12h and 14min.On the first day of September, sunrise is at 6:09 am and sunset at 6:37 pm. On the last day of the month, sunrise is at 6:13 am and sunset at 6:12 pm AST.
Sunshine
In Maunabo, the average sunshine in September is 9h.UV index
May through November, with an average maximum UV index of 7, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: A daily maximum UV index of 7 in September translates into the following instructions:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Maunabo, PR
- Average high temperature in September: 84.6°F
The warmest month (with the highest average high temperature) is August (84.7°F).
The months with the lowest average high temperature are January and February (79.9°F).
- Average low temperature in September: 78.1°F
The month with the highest average low temperature is August (78.3°F).
The coldest month (with the lowest average low temperature) is March (73°F).
Average pressure in September
Maunabo, PR
- Average pressure in September: 29.92"Hg
The months with the highest atmospheric pressure are January, February, June and July (30.01"Hg).
The month with the lowest atmospheric pressure is October (29.9"Hg).
Average wind speed in September
Maunabo, PR
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is July (9.7mph).
The calmest month (with the lowest average wind speed) is October (6.8mph).
Average humidity in September
Maunabo, PR
- Average humidity in September: 80%
The month with the highest relative humidity is November (81%).
The months with the lowest relative humidity are February and March (77%).
Average rainfall in September
Maunabo, PR
- Average rainfall in September: 3.62"
The wettest month (with the highest rainfall) is August (3.82").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in September
Maunabo, PR
- Average rainfall days in September: 20.4 days
The month with the highest number of rainy days is May (24.2 days).
The month with the least rainy days is January (12.8 days).
Average daylight in September /
Average sunshine in September
Maunabo, PR
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 13h and 12min).
The month with the shortest days is December (Average daylight: 11h and 6min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Maunabo, PR
- Average sunshine days in September: 7.4 days
The month with the most sunshine days is January (15.5 days).
The month with the least sunshine days is May (3.6 days).
Average UV index in September
Maunabo, PR
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August, September, October and November (UV index 7).
The months with the lowest UV index are January, February, March, April and December (UV index 6).
Average cloud cover in September
Maunabo, PR
- Average cloud cover in September: 34
The month with the most cloud cover is May (Cloud cover 42).
The months with the least cloud cover are February and September (Cloud cover 34).
Average visibility in September
Maunabo, PR
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





