Summer has officially arrived with full intensity! This Saturday, December 21, marks the summer solstice, signaling the start of the hottest season of the year in the Southern Hemisphere, particularly affecting Brazil. Not just bringing warmth, this day carries the title of the "longest day of the year." This phenomenon arises from the cosmic dance between Earth and the Sun.
The Earth does not rotate "straight" on its orbit; it tilts about 23.5° relative to the plane it uses to orbit the Sun. Though this detail might seem small, it significantly defines the beginning and endpoint of each season. During the summer solstice, the Southern Hemisphere is tilted at maximum toward the Sun, increasing the solar light we receive. Consequently, summer days are longer and nights shorter. Following the solstice, daylight gradually decreases until the winter solstice, marking the shortest day and longest night.
So why doesn't the summer solstice always fall on the same date? It typically occurs on December 21 or 22, but the exact date varies each year. This discrepancy arises from the difference between the civil year, comprising 365 days, and the tropical year, which lasts about 365 days and 6 hours. This accumulated difference is corrected every four years with the addition of a day to the calendar—known as leap year.
Equinoxes, representing balance between day and night, occur at the start of spring and autumn, offering near-equal light distribution across the hemispheres. With the summer solstice, the Brazilian population can prepare for longer days, elevated temperatures, and the vibrant climate many associate with the summer season.
The summer solstice also brings higher temperatures and anticipated rainfall patterns, especially significant for the 2024/2025 summer season. The summer is expected to feature more frequent rains across Brazil, with projections indicating accumulations exceeding 400 mm, according to the National Institute of Meteorology (INMET). They explained, "This period is characterized by rising temperatures nationwide, due to the relative position of Earth to the Sun, which is located farther south. This phenomenon creates longer days than nights, leading to rapid changes in climate conditions."
Further explaining the summer, INMET highlighted potential weather events: "The heat and humidity are expected to prevail across the nation, though not as severely as previous years during the El Niño phenomenon. Signs suggest the return of La Niña might impact the season. The latest projections from the National Oceanic and Atmospheric Administration (NOAA) indicate a 59% chance of La Niña forming by January 2025, transitioning swiftly to neutrality between March and May of the following year."
La Niña typically leads to reduced rainfall in the South, complemented by wetter conditions for the North and Northeast. The Southeast and Central-West may experience cooler and rainy periods, but the La Niña phenomenon is expected to be of shorter duration and weaker intensity than its predecessor between September 2020 and March 2023.
With summer underway, local governments are preparing to handle the surge of tourists. The São Paulo city government initiated its Summer Operation for 2024/2025, promoting infrastructural enhancements on key coastal routes to accommodate the expected heavy traffic. Luis Fernando Vanacôr, director of the State Road Company, emphasized, “We are taking various actions to allow families to travel safely and preserve lives, ensuring greater security for motorists, cyclists, and pedestrians.”
Preparations include improving road signalling and enhancing medical attendance on major highways to maintain comfort and safety during the influx of travelers heading to the coast.
Meanwhile, Nova Iguaçu's municipal government has also kicked off its Summer Plan, consoliditing efforts across safety, transportation, and public order sectors. The plan involves various local authorities and aims to create harmonious interactions between residents and tourists, preserving environmental integrity throughout the area. "This work organizes traffic and helps avoid accidents, which tend to rise due to increased alcohol consumption," commented local resident Edilza Bernardo da Silva, praising the initiative.
Simultaneously, the Nova Iguaçu Civil Defense Secretariat unveiled its Contingency Plan for protecting citizens against potential summer storms. Colonel Jorge Ribeiro Lopes elaborated, stating, "The plan outlines various strategies we've developed over the years, aiming to prevent disaster situations through effective communication and proactive support for affected individuals."
Rounding off the comprehensive summer preparations, authorities are equipped to manage peak periods effectively, highlighting key safety measures. With the summer solstice marking the start of what many deem the most vibrant season, regions like Brazil are gearing up for extended warm days, intermittent rains, and various community strategies to embrace and manage the season's challenges.
