September experiences a drop in rainfall from the peak observed in
August, signaling the onset of the dry season. The decline in rainfall is accompanied by a decrease in humidity. Notably, temperatures remain high, indicating the lingering effects of the summer heat. Despite receiving considerable sunshine, September sea temperatures decline to 29.3°C (84.7°F). As the wetness subsides and the weather begins to cool, September presents a pleasant period to visit
Hai Phong.
Temperature
As Hai Phong transitions into September, the average high-temperature stands at a still hot 30.8°C (87.4°F), offering little variation from the preceding month. In September, Hai Phong encounters an average low-temperature of 24.2°C (75.6°F) during the night.
Heat index
For most parts of September, the heat index is computed to be an extremely hot 43°C (109.4°F).
Precaution: Heat cramps along with heat exhaustion are possible. Heatstroke is a serious risk with continued exertion.
Heat index readings emphasize conditions of light breezes and shaded spots. The direct sunshine could escalate the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', offers an insight into how hot it feels when we factor in moisture content. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Given the impact of direct sunlight, it's noteworthy that the felt temperature can rise by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Children often lack awareness of the importance of taking breaks and rehydrating. The feeling of thirst is a late indication of dehydration, so maintaining hydration, especially during long periods of physical activity, is critical.
Evaporating sweat, an outcome of perspiration, is key in assisting the human body to moderate its temperature. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. Accumulating more heat than the body can dissipate leads to an uptick in body temperature, with potential heat stress consequences.
Humidity
In September, the average relative humidity is 87%.
Rainfall
In Hai Phong, in September, it is raining for 10.6 days, with typically 324mm (12.76") of accumulated precipitation. In Hai Phong, during the entire year, the rain falls for 104.3 days and collects up to 2209mm (86.97") of precipitation.
Sea temperature
In Hai Phong, in September, the average water temperature is 29.3°C (84.7°F).
Note: Surface water temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are considered superb and highly pleasant for water activities over extended periods.
Daylight
In September, the average length of the day is 12h and 16min.
On the first day of the month, sunrise is at 05:37 and sunset at 18:09. On the last day of September, sunrise is at 05:44 and sunset at 17:42 +07.
Sunshine
In September, the average sunshine is 6.3h.
UV index
In Hai Phong, the average daily maximum UV index in September is 11. A UV Index estimate of 11, and higher, represents an extreme threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum high UV index of 11 in September translates into the following recommendations:
Carry out every crucial safety measure. People with fair skin may sustain burns in fewer than 5 minutes. Avoid exposure to the Sun and try to stay in the shade between 10 a.m. and 4 p.m., when UV radiation is most potent, but be aware that parasols or canopies may not offer full protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. One must apply and reapply generously an SPF 30+ broad-spectrum sunscreen every two hours or after an outdoor workout or swim. Attention! UV radiation is ramped up when reflecting off sand and water surfaces.