Engineering works to fix a broken piece of railway track which had buckled as a result of the recent hot weather have now concluded allowing normal service to resume at Waterloo, reports Network Rail.
South West Trains say they do not expect any further delays to their services but are advising customers to carry extra water for their journeys.
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Tuesday's weather for the west of the region
Tuesday's weather for the east of the region
Tuesday morning's weather for the east of the region