Viana do Castelo — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Viana do Castelo, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Viana do Castelo today is 16.6°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Water Temperature Chart Over the Last 30 Days
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| SEP 14 | 18.5°C | 19.0°C | |
| SEP 15 | 17.6°C | 19.0°C | |
| SEP 16 | 18.1°C | 19.0°C | |
| SEP 17 | 18.0°C | 19.0°C | |
| SEP 18 | 18.6°C | 19.0°C | |
| SEP 19 | 16.7°C | 19.0°C | |
| SEP 20 | 16.7°C | 19.0°C | |
| SEP 22 | 19.0°C | 16.7°C | |
| SEP 23 | 19.0°C | 16.8°C | |
| SEP 24 | 19.0°C | 17.0°C | |
| SEP 25 | 19.0°C | 17.1°C | |
| SEP 26 | 19.0°C | 17.2°C | |
| SEP 27 | 19.0°C | 17.3°C | |
| SEP 28 | 19.0°C | 17.4°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 5°C | 9°C | 11°C |
| February | 5°C | 8°C | 12°C |
| March | 8°C | 11°C | 14°C |
| April | 10°C | 14°C | 17°C |
| May | 13°C | 18°C | 22°C |
| June | 15°C | 19°C | 24°C |
| July | 17°C | 21°C | 26°C |
| August | 18°C | 22°C | 27°C |
| September | 15°C | 19°C | 24°C |
| October | 12°C | 16°C | 18°C |
| November | 9°C | 13°C | 16°C |
| December | 5°C | 9°C | 13°C |
Viana do Castelo: Weather Forecast
September 21
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Viana do Castelo (Portuguese: Viana do Castelo), in the district of the same name on Portugal’s northwest coast, has a mix of coastal estuaries, riverine stretches and small inland lakes whose temperatures follow the Atlantic-influenced temperate climate. Freshwater bodies in the area typically register winter surface temperatures around 8–12 °C (46–54 °F), rise through spring to roughly 10–16 °C (50–61 °F), reach their warmest in summer at about 18–24 °C (64–75 °F), and cool in autumn to near 12–18 °C (54–64 °F). Actual values vary with depth, shading, inflows from rivers, and recent weather; shallow lagoons and sheltered coves warm faster than deep or fast-flowing sections.
Swimming is generally possible in lake and lagoon areas of the Viana do Castelo district but normally only in designated bathing spots where local authorities monitor water quality and safety. Permitted swimming depends on municipal rules, seasonal bathing water classifications and the absence of harmful algal blooms or bacterial contamination; lifeguards, signage and facilities may be present in popular sites during summer. Visitors should check current local advisories because cooler temperatures outside mid-summer, currents near river mouths, and occasional contamination events can make swimming inadvisable even when access is allowed.