// Export the image,
Export.image.toDrive({
  image: median12,
  description: 'december_median_ndvi',
  scale: 150,
  region: geometry
});

Any help would be appreciated.


//set map location
Map.setCenter(16, 7, 8);

var image_reduced = dataset.reduceToImage(['value'], 'mean');

Map.setCenter(16, 7, 8);
Map.addLayer(image_reduced, {
  min: 0,
  max: 1,
  palette: ['008800', '00FF00']});

// Use ee.Filter.calendarRange to filter by year and month. One variable per month and season
var january = dataset.filter(ee.Filter.calendarRange(2012,2018,'year'))
.filter(ee.Filter.calendarRange(1,1,'month'));
 var february = dataset.filter(ee.Filter.calendarRange(2012,2018,'year'))
 .filter(ee.Filter.calendarRange(2,2,'month'));
var march = dataset.filter(ee.Filter.calendarRange(2012,2018,'year'))
.filter(ee.Filter.calendarRange(3,3,'month'));
var april = dataset.filter(ee.Filter.calendarRange(2012,2018,'year'))
 .filter(ee.Filter.calendarRange(4,4,'month'));
var may = dataset.filter(ee.Filter.calendarRange(2012,2018,'year'))
.filter(ee.Filter.calendarRange(5,5,'month'));
var november = dataset.filter(ee.Filter.calendarRange(2011,2018,'year'))
.filter(ee.Filter.calendarRange(11,11,'month'));
var december = dataset.filter(ee.Filter.calendarRange(2011,2018,'year'))
.filter(ee.Filter.calendarRange(12,12,'month'));

// caculate one median image per month
var median1 = january.median();
var median2 = february.median();
var median3 = march.median();
var median4 = april.median();
var median5 = may.median();
var median11 = november.median();
var median12 = december.median();

var colorized = dataset.select('NDVI');
var colorizedVis = {
  min: 0.0,
  max: 1.0,
  palette: [
    'FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901',
    '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',
    '012E01', '011D01', '011301'
    ],
};

//add layers. they are in reverse order because that's how the layers are added
Map.addLayer(median12.clip(geometry),colorizedVis,'December');
Map.addLayer(median11.clip(geometry),colorizedVis,'November');
Map.addLayer(median5.clip(geometry),colorizedVis,'May');
Map.addLayer(median4.clip(geometry),colorizedVis,'April');
Map.addLayer(median3.clip(geometry),colorizedVis,'March');
Map.addLayer(median2.clip(geometry),colorizedVis,'February');
Map.addLayer(median1.clip(geometry),colorizedVis,'January');