The weather on the mainland is normally good from May until November. Afternoon breezes provide perfect conditions for safe and exciting sailing and boating throughout the season. In May there are wild flowers in profusion, and as June approaches there are fireflies and the water temperature is rising. Greater quantities of fruit and vegetables are available. In July and August warm seas have phosphorescence and high temperatures.  September and October see the start of the grape harvest and the valleys are carpeted with cyclamen. The bracken and olive trees remain green throughout the year. Sporadic showers can occur throughout the season. Summers in Achaia are reliably long and dry with brilliant sunshine and generally calm seas. This sort of weather usually lasts from May to October, with July and August being the hottest months. In spring and autumn there is generally plenty of sun although the temperatures are lower than in the summer. December to March is the wet and windy period. In summer the wind is usually very light in the mornings, picking up around noon and dying away at sunset.

Sea temperatures for swimming start at 18^oC/65^oF in May rising to 25^oC/76^oF in August and falling to 21^oC/72^oF in October. Occasionally the evenings may seem cooler so a jumper is advisable even during the summer months. Sporadic showers can occur throughout the season. As mentioned in a previous section, avoid the sun between 12:00 and 16:00, especially if you have sensitive skin

During the month of May and October you are most likely to experience good weather with pleasant average temperatures that fall between 20 degrees Celsius (68°F) and 26 degrees Celsius (79°F).

Facts from historical climate data about Rio:

• The hottest season / summer takes place in June, July, August and September.
• August has an average maximum temperature of 31°C and is the warmest month of the year.
• The coldest month is January with an average maximum temperature of 15°C.
• July is the sunniest month with an average of 358 hours of sunshine