Every year, the Nigerian Meteorological Agency (NIMET) releases a seasonal climate prediction report that provides valuable insights into what to expect in terms of weather patterns in the country. These predictions are crucial for various sectors, including agriculture, transportation, and energy, as they help stakeholders plan and prepare for the different weather conditions that may occur during the year. In this blog post, we delved into the climatic predictions for Nigeria in 2023, adapted from the report.
The Two ENSO (El Nino Southern Oscillation: a recurring climate pattern which involves changes in the temperature of waters in the central and eastern tropical Pacific Ocean) phases projected to have an impact on the length of the season, the end of the season, and the total amount of rainfall for the season in 2023 are the cold phase at the onset of the rainy season and a neutral phase. While the beginning is expected to be earlier than average, there is a 75–90% probability that the season's length, end, and total amount of rainfall will be normal. There is 75-90% that the weak cold phase will continue from December 2022 to February 2023 and decrease by 56% by March after which a neutral phase will begin with a probability of about 64% and increase by 74% By April -May – June season persisting till June – August season with a lower probability. The season is therefore likely to end in a warm phase by December 2023.
Pre-Onset Rainfall Activities (False Onset).
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The pre-onset rainfall season is often regarded as false onset because before the full commencement of rainy season each year, there are usually frequent rainfall events and this pre-Onset can come very early in the year. It could also heavy and fairly regular which most times could mislead the public particularly Farmers who tend to rush their farming activities. This occurrence of rains with varying intensity and frequency annually is normal. In 2023, more frequent high intensity rainfall before the commencement of the onset of the planting season is expected.
Onset dates of rainy season and departure from normal.
The 2023 onset of rainfall is predicted to be earlier than normal in most parts of the country with the exception some areas in Kastina, Zamfara, Kano, Jigawa, Yobe in the north and Cross river, Ebonyi, Imo and Rivers in the South that are likely to experience a delayed onset when compared to the long term averages in the area. The onset dates in parts of Adamawa, Bauchi, Gombe, Kwara, Oyo, Ogun and Lagos are probably close to normal.
This forecast indicates that the earliest onset will likely occur on or around 2nd of March, 2023 in the coastal zone of the south – south states of Bayelsa, Rivers, Akwa Ibom and environs. The inland cities of the south are likely to experience their onset in April while areas around the central states are likely to have onset in May. Some core Northern states are predicted to have onset between June and July with the northern fringes of Sokoto, Kebbi, Zamfara, Kano, Kastina, Jigawa, Yobe and Borno states are predicted to likely have onset between 20th June and 7th of July , 2023.
Prior to the onset phase, severe windstorms across the country and sandstorms in the core northern states can occur.
RAINY SEASON CESSATION DATE
Across areas of the south which includes Osun,Ondo, Edo, Delta, Imo, Bayelsa, Rivers, Akwa Ibom, eastern portions of Ogun and Lagos, Yobe, Adamawa, Niger, Nassarawa, and Kogi states included, an early end of season is forecasted. Across areas of Gombe, Kaduna, Kwara, Enugu, Anambra, western Ogun, and Lagos, an extended rainy season is forecasted. The earliest cessation in 2023 is predicted to occur around September 26 over sections of Sokoto and Kastina, while it would happen much later—between December 16 and 24over the majority of the coastal region.
Length of rainy season prediction and departure from normal
In comparison with the climatological averages, most places in the country are likely to experience normal length of season excepts parts of Kastina, Jigawa, and Kano states where shorter than normal length of season is excepts. A difference of about 10 days below the climatological normal is expected. The length of the growing season is also projected to be shorter in several areas of Lagos, Ondo, Delta, Bayelsa, Rivers, and Cross Rivers. The core northern areas are projected to have an average length of growing season of about 84 days while Bayelsa in the south –south region is expected to have the longest length of season of about 283days. Niger state, Nassarawa , federal capital territory and southern Kaduna might have the length of growing season vary from 170 – 320 days.
Predicted annual rainfall amounts and departure from normal
Normal to above normal annual rainfall amounts are expected over most parts of the country except in parts of Yobe, Jigawa, Kano, Bauchi and FCT that are likely to observe below normal to near normal annual rainfall amounts. Other states such as Nassarawa, Taraba, Kogi, Benue, Ekiti, Osun and Oyo as well as FCT are likely to have between 1190 mm and 1590 mm of rainfall in 2023. However, the core southern states which includes: Bayelsa, Akwa Ibom, Delta and Cross river are predicted to record annual rainfall amounts of 2700 mm and above. In 2023, annual rainfall amount across Nigeria is anticipated to vary from 420 mm in the far northernmost parts to 3120 mm in the coastal areas. Rainfall amount in parts of Yobe, Borno, Kastina, Sokoto, Adamawa, Gombe, Kano, Kaduna, Bauchi and Niger states are expected to be between the range of 420 mm to 1200 mm. Kogi, Kwara, Osun, Lagos, Ondo, and Enugu states will likely record 1300 mm to 2000 mm of rainfall. The coastal states of Cross Rivers, Akwa Ibom, Delta and Bayelsa as well as Imo state are likely to receive annual rainfall amounts ranging from 2350 mm to 3253 mm.
Dry spell 2023 prediction
After the onset of rainfall in southern Nigeria, a mild (8 days) to moderate (16 days) dry spell is likely to follow. A moderate dry spell of 14 to 16 days is anticipated over Ogun (Abeokuta, IjebuOde), Oyo (Ibadan, Iseyin, Atisbo, Shaki, Ogbomoso), Osun (Osogbo), Ekiti (Ado Ekiti), Ondo, Lagos, and Cross River (Ikom, Ogoja) states while in June to early July 2023, a severe dry spell which is likely to last over 16 days is predicted in the following states: Kebbi, Kastina, Jigawa, Yobe, Adamawa, Borno, Kwara, Oyo, Nassarawa, Plateau states while a moderate dry spell is predicted over Niger, Nassarawa, Gombe, Bauchi, Benue, Kogi. A mild dry spell is predicted over Ekiti, Edo, Ondo, Anambra, Ebonyi, Ogun and Imo state in the month of July as well.
Little dry season prediction
The little dry season of 2023 is expected to begin between 21st – 26th of July, 2023 in parts of Ekiti, Kwara, Ogun, Oyo, Lagos states.
Temperature Predictions
The impact of temperature is mostly experienced in the country during January, February, March, April, May. The cold season occurs in January while the hot season occurs in March, April, May depending on location within the country.
Climatic Predictions and Health
Malaria Vigilance
The occurrence and spread of malaria are influenced by temperature and relative humidity which are two climatic elements that are associated with the rainy season. When the relative humidity is greater than 80% and the temperature is between 25 and 32°C, the area is under close watch. A moderate level of alertness is advised in the area when the temperature is between 20 and 25 °C and the relative humidity is between 70 and 80%. Low vigilance is advised when the temperature is between 18°C and 20°C and the relative humidity is between 60°C and 70%, and no attention is needed when the temperature is below 18°C and the relative humidity is below 60%.
Meningitis
Menigitis is strongly influenced by temperature, relative humidity and concentration of dust in the atmosphere. Relative humidity less than 20%, temperature range within 25oC - 32oCand atmospheric dust concentration of 500 to 2000 µ/m3, high vigilance is required while relative humidity within the range of 20-40%,temperature of 20oC - 25oC and dust concentration of 200to 500 µ/m3 is required for moderate vigilance. When the relative humidity is above 40%, temperature is below 25oC and dust concentration is within the range of 50 to 200 µ/m3, low vigilance is required.. No vigilance is required is there is a significant amount of rainfall.
This climatic prediction report presents a picture of what to expect in terms of weather patterns in the country. These predictions have significant implications for various sectors, including agriculture.
In our next blog post, we will explore the implications and measures that can be taken to mitigate the effects of these predictions on agriculture.
