The Welsh Ambulance Service says it is "very concerned at the handover delays that have been experienced recently".
It is "concerned that pressure across all hospitals in Wales has a direct impact on the ambulance response that is able to be provided to patients who call 999 for our help."
"Ambulance crews continue to provide clinical care for patients as they wait to be admitted into hospital and we provide ambulance clinicians, where possible, to care for patients in emergency departments to support the nursing and medical staff in hospitals."
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Fog and mist patches will linger throughout the day, although there will be some brighter spells to enjoy later in the day.
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Fog patches and mist will develop overnight, but it will be feeling much milder than what it has done recently.