The invention relates to a welding method for implementing and monitoring a welding process, whereby a power source (2) and a feeding device (10) for the welding rod (11) are controlled by means of a control device (4), and whereby at least one control variable is measured or calculated from characteristic variables of the arc during the welding process. After setting a first and a second time interval (102) with different durations and a scanning rate for determining the values of the characteristic variable (100), the values of the characteristic variable (100) are stored with every scan, after which, at an instant (40), a first mean value (106) and a second mean value (107) are calculated from the stored values of the characteristic variable which lie in time intervals earlier in time than the instant (40) by the control device as the control variable, after which an upper and a lower threshold value (104, 105) is calculated starting from the first mean value (106) of the first time interval (101), and the control variable is then compared with the upper and with the lower threshold value (104, 105).